These were recreational divers on a private boat. Doesn't sound like O2 would have made a difference, but you can bet the Coasties had a bottle on their boat....
Which leads me to another lesson from this incident: you can't rely on rescue personnel to do jack. You have to tow your own line.
The Coast Guard DOES NOT carry O2 on their boats- at least in the Pensacola/Mobile area. That came straight from the CO during a meeting a few years back. If you transfer a "patient" to a coast guard boat and want to send your O2 with them, you must also send your own certified provider.