If you judge it to be jewelry the fact that he says it is for medical reasons is irrelevant unless it is a medical alert bracelet...no provision for "medical reasons" for jewelry other than m.a.b...if you do not judge it to be jewelry (and if there is no local interp saying that it is), then just judge if it is dangerous or confusing....

Who You Gonna Call? Mythbusters ...
 

Players may not participate while wearing jewelry. Religious medals or medical alert medals are not considered jewelry. A religious medal must be taped and worn under the uniform. A medical alert medal must be taped and may be visible. State associations may, on an individual basis, allow a player to participate while wearing a head covering, if it is worn for medical or religious reasons, provided that the covering is not abrasive, hard, or dangerous, and is attached in such a way that it is highly unlikely to come off during play. Written documentation should be available.

"On this next number I want you all to join in. Would those in the cheap seats clap their hands? The rest of you can rattle your jewelry." (John Lennon)

I doubt previous officials overlooked this...
 

If I had a quarter for everytime I heard that one, I could probably buy a large pizza.