my opinion, if they (those running the XC event) did not say something about it before the race then they should have not DQ them, there is a reason for the rule (the same rule exsist in soccer), you can easily break someone finger if their finger got between the braclet and your arm, so there is a safety reason for it, in soccer you could usually get away with a braclet if you taped it to your arm so there was no way someones finger could get caught and before every soccer game the ref would "look over" everyone (mostly checking to makesure the cleats where legal) but they would look for other things like this and tell you to remove them if need be (lost my chance to buy grateful dead tickets b/c of a ref that would not allow use to tape wrist bands down for the ticket loto)