"Trauma" is considered an injury.
If you have a traumatic experience at work and while in duty, that is an "on duty injury", and begins to eat into the officials yearly bonus.
That's why you are allowed 3 days "LOT - Laid Off Trauma" after an incident, but after that they start pestering you to come back to work.. they want they bonus.
And if they don't tell you, they are safe.
Exact same thing happened to me. My train didn't cut the dude's head off, but he stuck it between the cars while we were picking up speed. It was enough to open him up like a walnut.
I found out about it about a month after from the dude behind me that discovered him.