"Yes.. I'm aware."

It's not even said in a sarcastic sort of way. Inigo's brain is just still wrapping itself around this current situation, so it comes out somewhat slowly. In fact, Inigo seems to realise it sounds pretty dumb after a moment, and so he quickly adds:

"I just didn't think you'd want to patrol with me? I mean.. that's what you were about to ask, wasn't it?"