Remembering how the spring lock suits operated, Charlie reaches into the neck of the suit and sets off the spring locks, piercing Afton and killing him slowly.
The springlocks are set off because they are very very fragile and from the leaking ceiling in the game it dripped water onto the springlocks to activate them.
the spring lock incident happens in 1993 I think. If fnaf 3 takes place in 2023 and springtrap was stuck in the safe room for 30 years then that should be when it happens