Its all about minimising the danger, not stopping it. Its the nature of robot fighting that theres always a possibility for injury.
I would rather all robots had a system like beautys or LF/LHs to arm and them pull it out. it means theres no chance of missfires when the gas is let in (which some systems is likely). I would rather have 100kg on my hand than the full force of a flipper to the head or arm.Leaving the pin in until the last minute also minimising the time when the flipper is able to fire, so in my view, safer in every way.
Regarding locking pins for self locking systems is a tricky one that was talked about at a previous meeting.
I dont believe they need one, and as andy kane pointed out, to have a locking pin actually lock a hydraulic heavyweights crusher you need some beefy I-Beam or similar to stop it - and thats just not reasonable.
I have not seen a pneumatic robot pass a tech check without a locking pin since that meeting.