Diving is a contact sport . . .
. . . seriously, when you are gearing up, and when you are gearing down. Your slinging steel, nickel plated brass, and aluminum all over the place, and its easy to knock your wrist into something and not notice it, especially if your wearing your watch over a dry-suit or wetsuit. If your on a cattle boat with other divers, then you get a full on assault from the guy next to you, add if the boat is a rocking, ten fold.
That being said it is very easy to get your gear banged up and not notice it because your focused on so many things. Getting your gear together, getting in your gear, checking your budd's gear, sweating your but off, listening to the captain and divemaster, getting up, getting to the platform, getting your fins while the boat is a rockin, and then finally taking the giant stride. Thats just getting off the boat
If you are the occassional vacation diver, its even more stressfull, because not your doing on a regular basis.
Don't sweat the small stuff, get it fixed and move on, I know it sucks, BOHICA