Did anyone say you said anything untruthful? No, they just called you an asshole. You can both be an asshole and be right.

PS - Just some advice that I learned in sales 101 early in my career...focusing on shit talking the competition generally isn't a strategy that works well.

In case you were unaware, if someone's defense against being called an asshole is to say "well nothing I said was false" they're almost certainly an asshole.

No one accused you of dishonesty.