The one that I was involved with was the first start of the day, when I was flying with our squadron commander who was in the captains seat.
As well as avpin getting where it should not have been, the other little trick was instead of one of the Three cartridges in the breech firing as it should have (it gave you Three starts before you had to reload), all Three would go off together, and blow the breech apart.
If any one comes across a Belvedere in a museum, take a look at the panel fit, door and window operation, and standard of the riveting and general structure, it makes messrs Westland and Sikorsky products of that era look like they were built by amateurs.