I. A SYSTEM BUILT ON FAIRNESS, NOT PERFECTION
Injured workers often hear some version of this:
“WCB said they couldn’t prove it happened at work, so they denied it.” This misunderstanding is incredibly common—and deeply damaging. Many claimants, and unfortunately many case managers too, operate as though Workers’ Compensation Board claims must be proven
beyond a reasonable doubt. But that’s not the standard. Not even close.
WCB decisions are not criminal proceedings. You are not on trial, and
WCB is not a court. The correct threshold is called the
balance of probabilities, and it is deliberately and necessarily far lower than the standard applied in criminal law. That’s a good thing. Because if the bar were set any higher, nearly every claim would be denied.
The system is supposed to be accessible. It exists to protect workers—not to mirror the rigour of criminal prosecutions or impose impossible evidentiary standards. And yet, countless claims are denied every year because decision-makers forget that doubt is allowed.
II. DEFINING THE STANDARDS OF PROOF
Let’s break this down.
- Beyond a Reasonable Doubt is the standard in criminal trials. It requires such overwhelming evidence that there is no plausible reason to believe otherwise. In practice, this means that if there’s any genuine doubt as to guilt, the person must be acquitted. The purpose of this high threshold is simple: to protect the innocent from wrongful conviction. When someone’s liberty is at stake, society demands near-certainty.
- Balance of Probabilities, by contrast, is the civil law standard. It is used in lawsuits, insurance disputes, and workers’ compensation claims. It asks only whether something is more likely than not. If the evidence tips even slightly in favour of one side, that side wins. This standard accepts ambiguity. It doesn’t require exhaustive proof or eliminate all doubt—it simply requires that the evidence, on balance, leans in one direction.
Imagine a scale: if the weight of evidence is 51% on the worker’s side, the claim is compensable. That means there can be uncertainty, conflicting testimony, or inconclusive medical evidence—and the claim can still succeed.
III. WHERE WCB POLICY MAKES THIS CLEAR
WCB Alberta Policy 01-03,
Benefit of Doubt, puts this principle into black and white:
“When the evidence for and against an issue related to a claim is approximately equal in weight, the issue will be resolved in the worker’s favour.”
This is more than just a suggestion. It is a directive. Case managers are obligated to apply this principle when the facts are unclear. It recognizes that many work injuries and occupational illnesses arise under circumstances that don’t leave perfect evidence trails. Not every claim has a video recording or a witness statement. In fact, most don’t.
WCB is not allowed to use lack of certainty as a reason to deny a claim. If the facts are evenly split, the tie goes to the worker. If the worker’s version is more plausible than not, that should be enough. The burden of proof is intentionally low to reflect the protective nature of the system.
IV. WHY THIS MATTERS FOR WORKERS
The difference between these two standards of proof isn’t just academic. It determines who gets benefits and who gets left behind.
When case managers apply the wrong standard—requiring near certainty or ruling out all other possible causes—claims are unfairly denied. Workers who have legitimate injuries are told they lack “conclusive proof.” But the law does not require conclusive proof. It requires a reasonable conclusion based on available evidence.
Here are just a few examples of how this plays out:
- A worker develops a repetitive strain injury over months, but there is no single incident to point to. The claim is denied because it “can’t be proven.”
- A worker slips at work but doesn’t report it until the next day. The case manager finds the delay “casts doubt” and uses that to deny the claim.
- A psychological injury is reported without a specific traumatic incident. The claim is dismissed due to lack of a triggering event, even though the diagnosis is clear.
In each of these cases, there is room for doubt—but that should not defeat the claim. That’s the entire point of the benefit-of-doubt standard. When the evidence is incomplete, but still tips toward work as a contributing factor, the worker is supposed to win.
V. THE PURPOSE OF A WORKER-CENTRIC SYSTEM
Workers’ compensation is a no-fault insurance system. It was created as a compromise: workers gave up the right to sue their employers, and in exchange, they were promised a simpler, fairer, more accessible route to benefits when they get hurt. This means the system is supposed to be generous, efficient, and responsive to the realities of working people.
Unlike courts, WCB is not meant to be adversarial. It is an administrative body charged with making fair and timely decisions based on incomplete, imperfect, and sometimes ambiguous evidence. Requiring airtight proof undermines that purpose.
Workers’ compensation recognizes that work may not be the sole cause of an injury or illness. It just has to be
a contributing factor. That’s why the law says “arising out of and in the course of employment” rather than “caused solely and directly by employment.”
If the threshold were too high, the system would fail its purpose. Thousands of deserving claims would be denied, not because they weren’t work-related, but because the evidence wasn’t flawless. That is not justice. That is gatekeeping.
VI. EXAMPLES THAT ILLUSTRATE THE STANDARD
Let’s look at how the balance of probabilities plays out in real-world scenarios:
- Cumulative Repetitive Injury: A manufacturing worker develops wrist pain after years on the line. She also plays piano occasionally. The employer blames piano playing. But if it is more likely than not that the repetitive work tasks contributed, that’s enough.
- Mental Health Claim: A police officer develops PTSD after years of attending traumatic scenes. There’s no single inciting incident. The claim is denied because WCB wants a clear triggering event. But under presumptive PTSD legislation for first responders, and the balance of probabilities standard, the cumulative exposure is more than enough.
- Aggravation of a Pre-Existing Condition: A warehouse worker with mild, asymptomatic back degeneration experiences a sharp flare-up after an awkward lift. The claim is denied because “he already had a bad back.” But if the workplace lift aggravated the condition, even partially, it qualifies.
These examples are not about perfection. They are about what likely happened. That’s what the law demands—not certainty, but plausibility.
VII. TACTICAL TAKEAWAYS FOR CLAIMANTS AND ADVOCATES
Here’s how to use this standard to your advantage:
- Frame the Claim Properly: Always come back to the central question: “Is it more likely than not that work contributed to this injury or illness?” That’s the only question that matters.
- Cite the Policy: Reference WCB Alberta Policy 01-03 (Benefit of Doubt) in your appeal letters or submissions. Quote it directly. Remind decision-makers of their obligation to resolve uncertainty in favour of the worker.
- Challenge Unfair Denials: If a claim is denied on the basis of inconclusive evidence or speculative alternative causes, push back. That is not a legitimate reason under the standard of proof.
- Don’t Be Discouraged by Doubt: Lack of absolute proof does not mean lack of merit. WCB must accept claims even when doubt exists—if, on balance, the evidence supports the claim.
- Use Analogies: The “scale tipping” analogy is powerful. If the scale tips even slightly in favour of the worker, that’s enough. You don’t need the scale to slam down on one side.
VIII. RECLAIMING FAIRNESS IN WCB DECISIONS
The WCB system was never designed to operate like a courtroom. It was built as a shield for injured workers—to catch them when they fall, not to interrogate them for falling. And yet, time and time again, the standard of proof is misunderstood, misapplied, or outright ignored.
Balance of probabilities is not a loophole. It is the rule. It exists to account for the realities of injury, illness, and evidence. Most of the time, we don’t get tidy narratives and irrefutable documentation. We get shades of grey. That’s what this standard was built to handle.
Every claim should be approached with one simple question:
What is more likely than not? If the answer points to work, even if only slightly, the claim must be allowed.
Doubt is allowed. Fairness demands it.
