It's the first mover's advantage. When someone reports you everyone becomes suspicious and if you try to use the same tactics you get scoffed at and ignored.

I can't even remember. Certainly, nothing intended to cause offense. And that's where things go off the rails. Intent matters. This is how comedians can get away with saying things that a normal person cannot, because a "performance" puts things in a different context. And this gets to my point: it is easy to take offense at most anything people say, if you twist it out of context and put your own spin on it.

As mentioned in another comment, the "first mover advantage" matters when it comes to these matters. The person that initially frames the issue will be given more credence in most cases, because we as a culture have pretty much taken a shit upon the whole notion of "innocent until proven guilty".