When Lee and Ben found the guy in the Train, I didn't get a clear first look at the picture on the wall and thought it was the same picture from Clementine's house. Then I remembered she said her Dad was an engineer, and this guy could have been a train engineer. He could have also fled from savannah in the train to find clementine, but he failed when the train crashed. It would have been interesting if that was case, it's too bad it wasn't.
Edit: Dear everyone: I meant the engineer in the front of the train, not chuck. Lrn2read.