This is a video of the end of Mifsud's 11:35 breath hold: https://www.youtube.com/watch?v=MHPGKb7ipgc . The protocol after the hold is that you have to take off your goggles/mask and noseclip, look at the judges and do a clear hand signal that you're ok. Your chin/face should not touch the water before you get a reply from the judges, in the form of a card. It's nothing short of amazing how clearly he follows protocol given that his brain has been oxygen deprived for more than 11 minutes.
Regarding Mifsud, he had a YouTube channel, in French, which is full of information about freediving ! He worked a lot with scientists to understand how his body work and how to reach this world record. Also he confessed that he does not have spams when holding breath, so it helps a bit.
I don't mind live coding for students, but it often diverges a bit, I'd rather stick to what's on the repo I prepared with atomic commits.