Dude was probably weak as hell for sure. A lot of us could probably push him out of the way decently easy. DC is only 5'10" so I don't think height has a lot to do with how good a fighter is or how strong they are. Its all about the person in any circumstance.
You are correct, just because someone is shorter doesn't mean they are weaker (and the shorter man will usually be stronger at the same weight than a taller man) but that guy was just listing his aprox height and weight, (hell he's probably lucky to be 160), and when you are shorter your frame is likely to be smaller as well (which in this case It def is).