Likewise my Company showed this video as part of our refresher training. As stated, it is a non event apart from the startle factor from the noise.
I look at these photos and I do NOT say "Fools, they were so careless". I look at the photos and say "That could definitely happen to me!, I must make a mental note to be even more carefull performing the before start checklist"
Flight Deck Windows & Cockpit Door.....................Locked!