I doubt your "suicide by train" theory. Here is a story of two women walking on the tracks who were both killed -- according to the story they saw and heard the train, but they just froze in place until they were hit and killed. It's an odd reaction, but I guess it happens from time to time.
I don't think it's an odd reaction at all. In the wild, if you see a train and become perfectly still, sometimes they won't see you and they'll leave you alone and keep going on wuth their business.