finbob,
By all means, proceed as you see best.
My observation, however, would be that your inquiry here on SB appeared to be focused on the development of protocols for your own safety and decision-making.
While your adventure may have been alarming in retrospect, you described it as "exhilarating" at the time. You also noted that your escort to the deeps was disciplined.
My point is that you descended with the other diver, and have learned an interesting lesson. Unless you feel that additional punitive actions would be somehow constructive, you may wish to simply focus on what you yourself can take from this episode, and how you wish to plan your dives and u/w communications in the future.
If you feel punitive actions are warranted, so be it. But the lesson-learned here, I submit, is personal in nature and need go no further to be both efficient and effective.
Your mileage may vary,
Doc