It's a deliberate act of dominance. There's that other chap who just sets his phone up in cafes and restaurants to deliberately tape waiters calling him sir.
When you can call service providers just doing their job 'transphobic' and get them apologising and anxious, it's a gift for some men.
In this instance, the delta employee held the actual power because Dorfman needed the flight.
What did he say? That Dorfman was condescending? Interesting that he's recognising that the behaviour is wrong and that he can say so.
It is wrong. And hopefully more people will say so.