Poomermon said:
Sure. Interestingly, the wikipedia entry for negligence, under the heading "legal causation", deals exactly with this issue, and incredibly, a very similar case: http://en.wikipedia.org/wiki/Negligence
It is reasonably foreseeable that he might be flung around by the train. I guess distances involved etc would be important - if he flew for 200m, say, then damage would be less foreseeable if he got hit just beside a very busy platform. Furthermore, I believe its the case that if you can foresee damage to others, and damage happens to them, even if it wasn't in the way foreseen, you can still be held liable. So, for example, if maybe you thought you might derail the train, or something, and it crashes into the station as a result, then you might still be liable for damage from your satchel hitting them, or something.