Yeah, you can see that adrenaline still pumping when he’s see Mycroft. He’s still itching for a bit of a fight and still willing to do more for Sherlock even though he’s already saved his life that night.
I could write dissertations on John Watson. He’s so far from the simple guy he appears. So willing to protect some people no matter what, and yet so willing to let others, to quote Moriarty, burn.