The problem with holding a company criminally liable for anything is finding exactly who was the cause of the issue.
According to this wiki page for Comigel, the contaminations were a result of meat from suppliers. Did they know that they were being supplied with horse meat? If not, is the supplier in trouble for fraud, or is the processor guilty due to their inability to screen their meats?
Also, from how high of a position was this decision made? Was it not a "contamination" and did the CEO know about it, or was it due to the laziness or cheapness of someone under him? Who was really at fault for the issue?
In other cases, it can be even more hazy. If a faulty product kills someone, whose fault is it? Is it the person making it, because they did a bad job? Is it their supervisor for their failure in properly training employees? Is it QA, because they didn't catch the fault? Is it the plant manager for having incompetent staff? Is it the CEO of the contractor for having incompetent plant managers? Is it the CEO of the main company for hiring lazy contractors? Even then, is it the CEO that's the problem?
When someone goes out and deliberately frauds or harms another person, it's easy to throw the guilty party in jail, because it's one or a few people whose guilt can be determined. When a company does it, finding the individual at fault is finding a needle in a haystack, because it involves figuring out who, in a sea of hundreds of people, are responsible for a single decision.