I quiver when I see comments about snorkels being a worthless tool. As we certify more people who are less than comfortable at rhythmic breathing (snorkel/fin allowance), we will stress more divers at the surface who can not breath well because they have not mastered rhythmic breathing.
I freely admit, that I was certified using mostly the back stroke. Now that I've got the crawl stroke down well, and feel much more comfortable on the surface.
We should not laugh at people who, for their own safety, uses a snorkel. All it takes is "gasp, cough, gasp, cough", and a diver on the surface is loaded with anxiety and fear.
Certainly, we do not know more details about the victims age, health, medications, medical history. But either a regulator in his mouth, or a dry snorkel - and his heart rate should be alot lower.