Plenty of people go to Taj with first time cenote divers because it’s a very short dive and all but the biggest air hogs can easily do t with plenty of reserve to spare. It’s also a straightforward dive with several obvious get out of jail free cards. It’s much bigger than you think, but itNs dark sonit seems much smaller.
You may have thought that you were well out of the light zone, but when you’ve got your own light, as well as the DM using a canister light, it a dark cave, it can be difficult to actually see an exit until you’re literally underneath the cenote. One of the techniques learned in a cavern/cave course is to cover you light and let your eyes adjust, and after a couple minutes you can quite easily see an exit where you swore there was nothing but cave. Taj is a dark cave, but well lit on all but the darkest of days. It’s not nearly as “bright” as other caves in the area, places like Ponderosa or Dos Ojos, where other cavern tours are quite popular.
It sounds like a breakdown in communication. How did you indicate that you had a problem? Did you give the universal, “something’s wrong” sign and point to your ears? Have you had trouble equalizing before and did you tell him before the dive? At what point did he put you into touch contact? (Sorry, on my phone and can’t see your original post) Do you remember if this was before or after a left hand turn with opposite facing arrows in the line?
The scenario you describe where he grabbed you by the arm and swam you out is textbook touch contact, and exactly what you do if you need to swim a diver out of a cave, either due to a loss of visibility, or a “rescue” scenario. If you were having trouble maintaining neutral buoyancy, especially in a cave with rapid depth changes like Taj, and you seemed to be having issues, I would have probably reacted in the same way. It seemed as though he made a determination that you were unable to complete the dive safely and without issue by yourself, so he did his job and safely swam you out of the cave. He should have briefed this protocol, i’m guessing he didn’t.
It sounds more than anything like a lack of communication before, during, and after the dive. And it seems that from his perspective you were in trouble and, being completely unprepared and unequipped to deal with the issues yourself (not a slight, you’re not a cave diver, it’s to be expected) he did his duty to manage the situation as any cave trained diver would, get into touch contact, take control of the diver, and exit. That you are unaware that this is how these situations are expected to be handled again demonstrates the breakdown in communication.
Again, on my phone so i’n Trying to respond to your OP from memory.