A tip I give people for the sim in case this should occur, (Engine failure, no vibration, all spools stopped):
If you’ve done the Severe Damage memory actions and the sim instructor questions it, tell them you felt airframe vibration. It’s impossible for the instructor to prove that you didn’t (especially if the other pilot backs you up) and you’ve then met the conditions for Severe Damage. It should then turn into a discussion if the instructor feels like pushing it.
As I said earlier, this situation is a sim only gamesmanship issue. In the real jet, if both spools suddenly stopped there would most definitely be vibration. Severe Damage would be the correct and obvious action.