Drinking was a sacred activity, so when Michael had to pollute the ritual with unwanted company -- well, actually, after a certain number of drinks where he was and who he was with ceased to matter, so it was a win/win situation in the long run, but still, there was an event horizon of sobriety to get past -- he was less than pleased. On one hand, drinks. On the other hand, Harry bleeding Potter.
He went to the address Potter had given him. Of course he did. Drinks always won, plus, Potter would probably only try to condescendingly talk about peace and how violence wasn't an option again, and if he was going to do that, Michael wanted it to be person to person.
You couldn't punch a journal and expect the handwriting to say 'ouch'. Just for starters.
"Of all the gin joints -- wait, wrong movie," Michael said once he'd found Harry already sitting in a booth. He signaled a waiter before sitting down and because it was never too soon (and in this case, far too late), he took Harry's half-empty glass and took a long, completely necessary drink. "Fancy running into you here, Potter."