Actually, it wouldn't take ALL of them to make him lose his bid, only 1 of them played at the appropriate time, and the chances that 1 of the 7 were dealt aren't nearly as bad... It would really only take 2-3 of them being dealt (and split up appropriately) to make him lose the point.
I am not willing to get involved in all the permutations at this point (nor would I profess to be that qualified)... But I think it would have been a safe bid at 0 or 1 and depends on how much you trust/know the game and way people play it to know whether to risk 1 or not.
People here seem to overbid a lot, so getting 1 on a J of Trump isn't always easy. Mostly due to everyone scrapping for tricks...
By the By - I'd have bid 1 with it, but that's me.