When is a "know it all" actually a know it all?

I have had a few debates with a certain guy lately via FB comments & so far it just happens that I’ve been the one who presented the facts in the arguments & proved the other guy wrong. (that isn’t always the case but in the last few I’ve miraculously managed to be right & factual)

Now this guy doesn’t comment on my statuses but he will post a counter status and then in the discussions on his page with his friends he makes a snide remark about people who are “know it all” types and then generalize/insinuate to my status.

I’m wondering – though they really may not know it all – does it make sense to call someone a “know it all” if they actually do know more than you about a topic via both facts/research & experience? Doesn’t it make a person look as if they have some ego issues if they behave this way, rather than simply deal with their lack of knowledge and try learning something new for a change?