BTW, my comment said nothing about "queers" as you referred to them.
How about someone on board the train brain beaned the engineer while he was looking forward blowing the train whistle, rendering him unconscious, set the throttle to the 8th notch, left the gay guy for dead, made his way to the rear of the train and is among the survivors. The engineer may have just had time after coming to to react by trying to slow the train down.
Lets see, so far we have projectiles coming through the windshield, now we have terrorist on board sneaking up KO's the driver, jamming the throttle down then sneaking back to their seat.
Hmmm...If you're going to hijack a train on a suicide mission, why run back to your seat?
Makes about as much sense as any of the other assumptions and there are a great many unknowns.