In the scene in which Seraph, Morpheus, and Trinity first meet the trainman, he pulls out a small revolver and says "get away from me." He then proceeds to run out of the train, and when the good guys chase after him, he starts shooting at them. The problem is, he shoots 12 shots at them without ever reloading once. No revolver that small can hold 12 bullets.
Have some common sense. I've said this before and I'll say it again. This takes place in THE MATRIX. Things can happen that don't obey the laws of the real world. You can't call this a slip-up. Computers have glitches and the matrix is like a computer.
I noticed the revolver thing too, and also considered the whole "matrix - anything is possible" theory as well. I guess the trainman just reloaded while we wernt watching :S. By the way, if you watch when they chase him off the train, you see an advertisment for "Tastee Wheet". Mouse would be proud...