On the commuter rail I take, I had engineers tell me they're taught not to brake for suiciders on the tracks, because of the risk to all the passengers (many are standing, luggage is often not well secured, etc). So the greater good is to just hit the person on the tracks, stop at the next station, and call the police to come handle the incident report. They're only supposed to hammer the brakes if risk presented by whatever they're hitting is worse than the risk of braking to the passengers.

Apparently it really messes with many of them since it's human nature to try to avoid it, even though the only way to avoid killing the person is for the person to have second thoughts and dive off the rail bed. Getting told their primary duty is to the passengers under their care only does so much.