I think it should highly depend on the severity of the insult.
Please explain. I would like to know what constitutes as an insult that is ever "okay"
When are you making a point, discussing Bitcoin, is it possible that an insult needs to come into play. Hell, I think you can have a very strong opinion on another person that is very negative, and say that without directly or intentionally insulting.
It should also depend on the context. A remark, which might be intended as a joke, can be quite offensive to a person yet another might see nothing wrong with it. Especially when people hardly know who the other person is, it's quite possible to come across as insulting or offensive due to cultural/social/religious context without really meaning to.