This could be a fun (or un-fun, depending on personal taste) semantic argument, but IMO, the real gameplay is over the second you pull the final rivet on 21-6. That finishes the job.
To me, "the moment" isn't when Jumpman dies, it's when the timer bugs out. You can see Jumpman stop cold and spin around due to a timeout death anytime you want, but that 100/4000 timer flash is the defining element of the kill screen because it doesn't happen anywhere else in the game.
As far as HOW you die once you're on the kill screen, I don't think it matters. You're already dead.