Can corporations commit murder, or manslaughter?

In 1992, 26 coal miners were killed when the Westray Mine in Nova Scotia exploded.  A government appointed inquiry into the explosion concluded that the disaster was avoidable and that the employer’s representatives were aware that the mine could explode, yet continued to send workers down and failed to take the necessary remedial steps.  However, criminal charges filed against the corporation and the senior officials were dropped when the Crown concluded it could not obtain a prosecution.
These events led to a focus in Canada on the inadequacy of our criminal law when it comes to killings taking place at work that are due to the failure of management to take steps to avoid obvious risks.  The main problem, from a legal perspective, was that the existing test for finding organizations criminally liable was almost impossible to prove.  The leading case was Canadian Dredge & Dock. That test required the Crown to prove that a single person, who was a ‘directing mind’ (a senior official responsible for the management of the business) both had knowledge of the illegal act that causes the death and possessed the  ‘guilty mind’ or intent (the mens rea) necessary for a criminal offense.  It was virtually impossible for the Crown to prove those conditions were satisfied.  As a result, corporations were rarely found guilty of criminal offenses.
In the wake of Westray, both the Federal Conservative party (then in opposition) and the Federal N.D.P. introduced Private Members’ Bills calling on the Liberal government to amend the Criminal Code to make it easier to convict corporations of criminal offenses.  The Bills were debated in Parliament and in Committee meetings (yours truly was retained by  the United Steelworkers to draft a research paper and appear as an expert witness in the Committee meetings.  My testimony can be read here).  Eventually, Bill C-45 was passed.  A main feature is that it changed the legal test for finding corporations criminal responsible by expanding the ways in which the act and intent can be attributed to a corporation.  For example, it created a legal duty for individuals in organizations to take “reasonable steps to prevent bodily harm to workers.” This quick and dirty flowchart of westray bill explains how that works.
In last month’s Canadian Lawyer, there is a story about whether C-45 has been an effective deterrent and led to proper punishment.  The story discusses the first case in which a company was prosecuted under the new law (R. v. Transpavé Inc.).  A worker was killed in that case when a safety device on a machine was deliberately disabled, and although it was not proven who disabled it, the evidence  was clear that management knew people disabled the safety in the past and that senior management people had disabled it themselves in the past. The company was charged under the new law and pleaded guilty.  The Court ordered a $110,000 fine.
The debate in legal circles is whether a fine is an appropriate penalty.  Fines were already possible under occupational health and safety regulation, so did the criminal charge make any difference?  One problem with fines is that, if they are too small, they have little deterrent effect, but if they are too big, they may cause employers to go bankrupt or to layoff workers.  Should senior officials of the company have been imprisoned?  That is possible under this law, but no one yet has been sent to jail.