What Does the Crown Have to Prove in an OHSA Prosecution?

As many readers are likely aware, the burden of proof is on an employer to establish “due diligence” in an OHSA prosecution.  However, before the issue of due diligence is considered by a Court, the Crown must prove beyond a reasonable doubt that the employer committed the violation of the OHSA that has been alleged.

In the vast of majority of cases, the Crown does not have a difficult time proving beyond a reasonable doubt the employer breached the OHSA.  For example, in a machine guarding prosecution the Crown simply has to prove that the machine did not have a guard.  Not surprisingly, the Crown generally does not have a difficult time proving that a guard was not in place.

Once the Crown has proven that there was no guard in place, the burden of proof shifts to the employer to prove that it was duly diligent by establishing that all reasonable precautions were taken to ensure compliance with the OHSA.   The outcome of most OHSA trials turns on whether the employer can prove due diligence.

However, there are some cases where the question of whether the employer has actually contravened the OHSA is in dispute.  There have been a number of cases related to status of an entity under the OHSA where the Defendant has argued that the Crown cannot prove that it is the “constructor” or the “employer” under the OHSA.

However, there have been relatively few cases where the question of what the Crown has to prove in terms of causation of the accident has been in issue.  It is not uncommon for the Crown to argue that the fact that an event has occurred is proof of a contravention.  For example, in a guarding case the Crown will typically argue that the fact that a worker’s hand was caught in a machine is proof that the machine was not guarded.

However, in one recent appeal case the court has opened the door to imposing a more rigorous burden on the Crown in certain types of cases.  R v. EFCO Canada Co. et al.[1] related to a bridge which collapsed as a result of a failure of the lateral falsework.   Falsework is the structure and bracing required for the support of the formwork on the bridge.   The Defendant employer was charged with failing to ensure that the falsework was constructed in such a manner that it could withstand all loads to which it was likely to be exposed (i.e. would not collapse under expected loads).  An in-house engineer for the employer faced related charges under the OHSA.

The evidence at trial was that there were two separate types of falsework used on the bridge.  One type was provided by the Defendant employer and the other type was provided by a third party that was not before the Court.  The employer adduced expert evidence at trial which pointed out that the opinion evidence relied by the Crown did not consider the falsework from the third party and that the falsework provided by the third party could have caused the accident.

The Crown successful argued at trial that it was not required to prove how the accident occurred.  The trial court accepted the Crown’s argument that the fact that the bridge collapsed was enough to prove beyond a reasonable doubt that the Defendant’s falsework system contravened the OHSA.  The employer and the engineer were convicted.

On appeal, the employer argued that the trial court made an error of law by imposing an obligation on the employer to prove that the employer’s falsework system did not cause the accident.  The appeal court accepted the employer’s argument and ruled that the Crown should have led evidence which addressed the integrity of the falsework provided by the third party.

This case opens the door to a question of whether the Crown can continue to rely on the fact of an event as proof of a contravention.  This currently happens routinely in fall protection prosecutions where the Crown has repeatedly been successful in convincing courts that the fact that a fall occurred is proof in and of itself of a contravention of the OHSA.

In EFCO, the appeal court focused on the fact that two different types of falsework were present and indicated that specific evidence addressing the third party falsework was required.  Interestingly, the appeal court said that had there been only one type of falsework, the Crown would have been able to rely on the collapse of the bridge as proof of the contravention.

It is clear that the appeal court has not closed the door to an argument by the Crown that the event proves the contravention.  We expect that such arguments will continue to be common in fall protection and guarding cases.

However, in cases where there are a number of potential causes of the event, it appears that the burden is now on the Crown to prove that the contravention caused the event in question.  It is our view that this decision makes contraventions involving such events as explosions and collapses more difficult for the Crown to prove.

It is our understanding that the Crown is seeking permission (referred to as “leave”) from the Court of Appeal to pursue a further appeal of this case.  In light of the general importance of the issues in this case, it seems likely that the Court of Appeal will agree to hear it.



[1] R. v. EFCO Canada Co. et al., [2012] O.J. No. 134 (S.C.J.)

Related Posts