This is an important point that people often misunderstand in internet arguments. Attacking or insulting someone is probably not a good idea in general, but it doesn't constitute an "ad hominem" and doesn't affect the rest of the argument presented unless it's being argued that the other person is wrong because e.g. they smell bad. If it's just mentioned that they smell bad and they're wrong for other reasons, it's not that fallacy.
I do understand that in order for an argument to be fallacious it has to actually be part of an argument.
There's a bit of subjectivity to this. Generally when someone makes an argument and the response is merely "you're a hypocrite", the inference is that person #2 believes that person #1 is wrong and that's the best counter they've got. I understand there's some inference on my part, but that's how I usually see it.
Someone does not have to literally say "You are wrong because you're a hypocrite" in order for the fallacy to apply.
See, looking over this thread I see lots of "You are wrong, AND you are a hypocrite" but relatively little "You are wrong BECAUSE you are a hypocrite".
