One aspect that no one has mentioned: professional engineers and conductors have access to company-provided counseling when they're involved in fatal crashes. If you're any sort of normal human being, you would have tremendous feelings of remorse for having been involved in a fatal incident, even if objectively you know the fault isn't yours. The OERM people are volunteers though, donating their time to a non-profit organization, and one that probably isn't sitting on a mountain of cash. Where are those volunteers going to get psychological help if they want it?