I have a couple issues with this situation which will impact my verdict:
1. It looks like there was some kind of conversation that was ongoing. Obviously I don't know what was said prior to this, but that tells me there's a little bit more than meets the eye.
2. Assuming staff were on, I'm unsure as to why this wasn't just handled in game.
These two points lead me to believe that something else was happening and that I'm not getting the full picture, which I don't like. However, Don still shouldn't be calling you that. On the flip side, this is not "heavy player diss" it looks like an argument and Don threw an insult your way. With all of that in mind, I will accept the player report and issue a verbal warning for player diss.