The guy could have asked in a nicer way, but to be fair you were just as rude to ignore him and do whatever you wanted. The whole bad experience could have been avoided if you'd just replied to him and had a conversation about it instead of just going off and doing w/e you wanted.
This is a team game. You as a tank can no more do the run without your dps than they can without you or the healer, or the healer can without the tank or dps.