Doc says wait some time (3 weeks?) and see if it's shifted. If not he recommends letting it heal in place, which would result in a permanent "chip on my son's shoulder," as the doc says. Or we can elect surgery, but really just for aesthetics.

My son did both (i) avoid ibuprofen, solely on the say-so of people on the internet, electing Tylenol instead, and (ii) avoid the ER, seeing only the general practitioner to get a referral, and our ward member orthopedic surgeon.

We did find a sling we'd used for a prior injury and he's in it now, and has been since last night.