Mulan, I don't think that you have the ability to act in a malicious way, it just doesn't seem to be in you.

It sounds to me like a simple personality clash. We, even here, don't get along with everyone....

In your story, it sounds to me as if you were simply trying to come up with solutions to a problem and he was just moaning about them.
You were not mean or a mean person.

AND in future, simply because a person DOES something bad, doesn't mean that they ARE bad.

Huge difference.