You inflate the BCD in a silt out so you know what's up (and down)
You breath off the BCD in case of OOA, it gives you a few breaths before you pass out from hipoxia, old divers were taught to do this as passing out and drowning sounds better then just drowning.
You shut off the light so you have a chance of spoting sunlight, in a compleate siltout your light is useless anyway.
He is a trained cave diver and all the steps he did that people are laughing to are survival technics that can come in useful and were taught by old school navy instructors, mine included.
I can't believe how meen people are to someone who is obviously sharing a incident that shaked him and that can teach a valuable lesson. Shame on you all, you are the reason most dive incidents are not shared and studied.