That response surprises him a little. He wasn't expecting that given people's usual reaction. "He... is. Was." That part hurts. And makes the stabbing in his chest get worse when he remembers everyone else he's lost too.

And, yeah, Tony was known for getting in the face of enemies (and otherwise) bigger and stronger than him, taking the hit, and getting back up again anyway. "Uh - he probably would have words, but wouldn't have a lot of room to talk considering all of the things he's ever done." Peter reads a lot. He knows who Tony used to be.