We played around with a few different types of improvised weapons for a while in a martial arts class. You know, axes are devastating...when you can hit. They're also slow and unwieldy, and I'd expect even the most pathetic yellow belt in Bubba-fu to be able to drop a lightly skilled axe-wielding attacker; it's just too easy to get inside its effective range while the guy is dealing with leftover momentum from his last swing. Really, it's like you get to use all those techniques that work against slashing weapons at the dramatically reduced speed you learned them at. Flailing around with one in the confines of most train cars makes it even less effective as a weapon; way too many things for it to snag on.
As for the attacker's skill, outside of maybe the Swiss Guard, I'm not sure where one could go to learn to use an axe in combat more effectively than is intuitive, so I really doubt he was some sort of lumberninja.
