If you were in deco during intro you were already breaking many rules.
You and your instructor should have had better sense.
I don't recall you being there, so I wonder why you think you know enough about that dive to make the WA assumptions?.
At worst it would be one rule broken (deco at intro), not several. You can get into deco on 1/6ths and do it while staying on the mainline with no jumps at LR, especially on the second dive of a day.
The important piece of information to consider here however is that having a computer briefly step into deco mode at depth does not automatically equate to breaking the no deco rule. As I stated, I was not worried about it. What I did not state is that I was not worried about it based on previous deco experience (not the norm at the intro level) and in particular with that computer, where I was confident with the cave profile on exit that it would clear from deco mode during a normal ascent before we ever reached the required stop depth.
Now, you can argue in a soft overhead environment that deco is deco as it prevents a direct ascent to the surface. But in a hard overhead that is harder to make that same arguemnent0 as a direct ascent is never an option anyway. If in the process of getting out of the hard overhead, at least to the first stop depth, you clear the required deco from the computer then there is no difference in the exit regardless of whether the computer decides for a few minutes at depth that you need a deco stop as there is no deco stop required by the time you get there. In effect, it does not change your exit or exit requirements in either an emergency or a normal exit.
The other thing that needs to be considered is that this was understood and anticipated when the dive was planned.
With regard to the rule, the time it takes to run into deco varies. For example, what if you are diving Nitrox using EADs and US Navy tables? That allows a lot more bottom time than most computers, but it does not require a mandatory stop. Would the same dive be both in compliance and in violation of the no deco rule depending only on whether you have a computer along, or depending on what table was used? How about if the computer is along only the backup?
That rule, like most rules, is not as black and white as many people would like to make it, what really matters is the larger issues that underpin the reason for the creation of the rule. With this this rule in particular, the deco itself is only a small part of the issue with the "no deco at intro" standard.
There are in my opinion, too many cave divers who break rules and too many cave divers who bend them, but the ones who worry me the most are those who do not understand them or their intent.
For example, an intro level diver could follow all the intro rules by taking a 1200 ft primary, run off the main line into parts of a cave that are tight (but not quite restrictions) and that are very silty. And he or she could do it while skip breathing to stay under 1/6ths. The end result will be a diver in O2 debt with high CO2 levels and increased suceptibility to both Ox tox and narcosis who is going to use a lot more gas going out than coming in even before you factor in the silt.
The diver will stay within the Intro rules, but it is irrellevent as it is not prudent and fundamentally violates the over arching purpose of the intro rules:
1. limit total penetration in order to limit the distance needed to exit in the event of an emergency,
2. to limit the diver to primarily established mainline pentrations, and
3. increase the gas reserve the diver has to adderess issues that may arise on exit.
The irony here is that some cave divers, in their zeal to not break any of the rules can find themselves developing habits that are detrimental to their over all future in cave diving - yet those who do not understand the rules or more importantly the intent, will not have a problem with it and will not call those divers on their questionable and unsafe practices.
And of course at the same time it appears that some cave divers will throw around wild accusations of multiple rules being broken based only on the knowledge that a dive computer went into deco at depth, with no additional knowledge.
One of the things I like about cave diving is that it is very exacting and demanding and rewards those who can think and who can also grasp the big picture while it is ruthless with those who cannot.
