I don't really think so. I'm quite sure people will report you for having too many cannons on your ship but you don't have an illegal amount of cannons on you ship so if you are checked I guess nothing will happen to your account (bigpoint can tell when you had how many cannons on your ship). Although there is a ban risk like with every bug/bot I guess the ban risk for this bug is very low. And even if you get banned you can easily argument by saying "I just bought ammo from the map, I couldn't know that there is a bug with this".
Long text short meaning: Very low ban risk, have fun with this bug