Fly4, please tell what that particular "joke" is? I've never heard it.
Are some captains deliberately instructing inexperienced co-pilots to call "Ground Ops" on 121.5? I find that very hard to believe, surely no professional pilot would be so stupid to incite someone else to do it, or get caught out by it - everyone does the air law exam before first solo!
I would also hope that by the time any properly trained pilot gets to CPL level they would have been taught to check their radio switches before transmitting. Maybe this isn't being emphasised enough, hence my question.