No, I think you are missing it.
They didnt zap him for saying **** You. They Zapped him because "**** You" was the response to the comply-or-get tazed command they issued him.
If a staff member of this board said to you "Comply with me Or I will suspend you." and your response was "**** You" you would not get Suspended from them for using foul language. You would get the suspension for non-compliance.
I think that I understand what you are saying. I disagree with the point that a tazer should be used to force compliance from non-physically resisting people. I think it is a step up on the force continuum. It would be like me telling a student to do something. Them telling me to **** off and me punching them in the face.
They may have been asking for it, but it doesn't excuse my actions.