Why do you think they would have fought immediately? If he trusted him — which was even easier to do when, as you say, he was injured and appeared not to be a threat — isn't it possible they left together on friendly terms?

Or, perhaps— Micah, we're calling him? If he did leave for some reason, Mr. Lavi could have gone after him with no ill intentions at all, only for something to happen later. I don't think we know for an absolute fact what it is that causes some people to awaken on Thursday nights, we just have theories.

And to your last point, if I might:

[ takes out his phone, scrolls to lavi's profile, and reads off: ]

Skills: fighting under duress (ex: broken ribs, limbs, concussion, internal bleeding).