You went from a counter person that was doing his job to a counter person that maybe wasn't.
I remember the day they put a one day super experienced diver on our boat going to Barracuda y San Juan - worst dive ever - but hey, the guy said he had all this experience.... I also remember a few instructors that had next to zero buoyancy control, a few that probably haven't taught in years, a few that looked like pool specialists......
You want to talk about the "AOW" certed divers I've seen??? The conversations I have overheard with "nitrox certified" divers? There is both terrible instruction and terrible absorbtion out there in the world.
Why did Pro Dive want you to get in the pool? Because they work out of a resort, they have a pool right there, it's quick and easy. Because you haven't dove in four years, I don't care who you are, they don't know you. They must not have a policy about private DM being standard for divers that have not been in the water, they probably don't have that policy because they have the pool. You know the other big red flag for me, you are not even nitrox certified - how can you be an instructor for so long and not nitrox certified? I don't understand how you don't see the value in teaching that to others? You have this old trust worthy computer, great, but it's 2023 and as an instructor, I would think you would want keep abreast of the real world and to pass that knowledge onto new students.
Pro Dive is a big operation that has bunches of happy customers that like to dive that way. They also run bare minimums so there is no extra DM to help you deal with any problems on descent, which now that you have dove here, maybe you understand those potentials. The big operations, Pro Dive, Dressel, Scuba Du etc.. get hammered locally all the time about their operations, divers and DM's - I applaud them for doing the right thing in screening divers.
How do we and virtually all other operators handle a situation like this? It's either a refresher or private DM. Because I'm too nice of a guy, if we had a full boat, I would have went along as an unpaid DM to see how the first dive went. Let me explain a little bit about here in Cozumel - everyone is so afraid to have a potential customer walk away, some are willing to cut any corner to get you on that boat, in that rental car etc....
So what did Aldora do? Either the front desk guy had no clue, didn't care OR which happens there: He/she knew there was a boat with two something DM''s or maybe even a boat with long time customers and they put you on that boat. Aldora does not work their DM and Instructor candadites but at times, it's nice to have them there as any extra set of hands/eyes and often the customer has no idea...... They also have boats with people that have 100's of dives with them, people that are well known. The odds are very great that you had someone there in case of a problem.....
As a fellow dive professional, I would expect a whole lot more respect from you for those in the dive industry. We are supposed to be leaders in the way we act and especially with safety - nothing we do is above anyones rules or policy.