If you go off the BSAC study, there were only 3 recorded cases of that happening over 10 years, which is part of what lead them to their "no primary donate" decision.
Sounds to me like their decision is being made off of a non-representational, small sample size group.
You need to be aware that the BSAC track incidents year on year and look for trends. They also extremely aware that low sample sizes can result in statistical distortions. Which is why it sometimes seems they are slow to change.
The incident report has resulted in the BSAC changing procedures over a prolonged period.
It's driven down boating and surface incidents quite markedly, which used to be truly horrendous.
AAS became mandatory, and Buddy breathing was dropped from the training scheme, as a result of the information the incident reports where producing.
Uncontrolled ascents have been reduced because of changes to the training scheme.
They also identified equipment issues in the past.
I can remember being taught to always donate the AAS in the direct line of site of the casualty, so that it was between the casualty and my face (blocking the casualties view of the regulator I was breathing from).
As I understood it, the reason for not teaching primary donate was far more complete than just the data from the incident report, which was one of the pieces of information included in the final decision. It included issues based around the diverse level of diving practiced by the membership. Trying to integrate divers of different levels within the same environment, trainees, and novice divers, with those doing technical diving. Equipment issues ,standard rig, long hose + twinsets, rebreathers, etc. Diving practice, most BSAC divers use Rich right & Lean left (rather than all stages on the left. I also believe the lawyers where involved with issues over liability over removing a working regulator from a divers mouth that might contribute to that diver being compromised in an incident, that was probably related to the standing rule, never put the rescuer at risk. I don't know the details, just the result.
