We were working on Deep. My understanding is that Advanced Open Water qualifies you to 100 feet and Deep qualifies you to 130. Realistically, 75 feet with crap viz in the dark feels deeper than it is.
I think as far as guiding the dive with the instructor present it's really a chicken or the egg question.
Does taking the course and mastering the material qualify you? or does going on 4 deep dives qualify you? In my opinion practical application with qualified supervision is an excellent method to improve skills.
Stating an objective and allowing the student divers to plan and execute the dive *WITH* the instructor present for planning, correcting plan deficiencies, and along for the dive makes more sense than saying " Okay kids, follow me to the lake bottom" and not looking back.
The instructor has a higher degree of responsibility when conducting deep dives, but I generally agree with your above statement. I tend to let my experienced students plan and take responsibility for our con-ed dives with coaching.
If the instructor happened to plan the the dive though, then that was the plan you should stick to barring a problem.
The reaction that the instructor had apon contact with you at the surface was unacceptable and immature. A calm discussion could have made it a good learning situation for all involved. I'm sure the instructor was really scared that he had lost you... His reaction was the release of all the worries he was having underwater whilst looking for you.
Ultimately you are a certified diver and reponsible for yourself.
You tried to signal that you had a problem and the other members of the team did not respond.
You took care of yourself and your problem (equalization) in a calm and collected manner. At the end of the day, everyone was safe and you didn't injure your ears.
Hind site is 20/20 so,
As you know, the rule of thumb when separated is to look for buddy for one minute before ascending. Perhaps if you ascended a couple of feet until ears felt better and waited for a minute or so, the instructor would have come back up, made contact and then either conducted the rest of the dive from that depth, or at least been aware of your ascent to the surface.
In the end, you should report the incident to PADI and the diveshop owner as well. Calling a client a ****ing idiot at my shop would be the last thing an instructor would do as an employee of my shop!
Brush yourself off, have fun, and keep diving! The situation you had with that instructor is definitely the exception, not the rule!