Kane, you describe what should happen to prevent the weapon from firing, not what can potentially happen. I am not aware of any robots electronics that has been designed as fail safe to recognised international standards so you have to assume something can go wrong. Therefore it seems very sensible to reduce the potential for injury to the operator by not having limbs inside the bot by the use of tools is a good starting point from my perspective and that is for both arming and disarming.

Dave, a locking pin is another topic in itself, M2 copied Bigger Brother amongst others by have the flipper locked in the open position until the bot was fully armed and then it was released. This again reduced the potential for injury during the arming process.