Perhaps someone with actual tech training will tell me that's all rubbish, but to my ignorant mind it makes sense.
No, Dirty-Dog it is not completely rubbish. Your ignorant mind works quite well. I am one of the tec-divers who is guilty doing my tec-dives mixed with rec divers. How it works, is that I always give the captain copy of my profile, so he knows how to plan the dives. Depending on my plan and current and other group, he tells me when I can jump in. I always trust captain and dove with him for years.
How we communicate emergencies? Every tec divers should have 2 markers red and yellow. The book says, that you should deploy yellow when your dive is OK and red in the case of emergency, but since so many rec divers use red as a regular one, we have an agreement with captain that yellow is for emergencies. On a buoy we can attach a note about the type of emergency we might have.
So, when captain sees my red (safe) marker, he can concentrate on his rec team. Actually I have been floating sometimes with my buoy for 20-30 minutes before I shall be picked up and I do not see anything dreadful in that. Maybe if you have too many curious burning molluscs around you, you do not enjoy this company too much. We have an agreement, that if our dive is OK, the rec divers have ALWAYS priority over us they are on holiday, having fun and this is how it should be. When you are a tec diver, you know better the risks and you accept them and try to be really careful in order to keep you diving for years.
About the discussion around this specific captain actions (involved in this case), please try to keep separate the theory of remote sites and practise in this specific case (when nearest taxi was only 10 minutes from the boat).
PS! Having tec divers on board is usually a good thing (we carry more oxygen, usually have ability to go for a deep rescue, on many cases have better training to evaluate the conditions of injured person, etc
), so we are not necessarily a risk, more likely an asset. Or maybe I am wrong?