I understand what all of you are saying about taking responsibility for yourself, however. we told this DM about 6 or 7 times that they were inexperienced and he ignored us that is why his fiance' and I buddied up ourselves. He has to have some responsibility in this as well being the EXPERIENCED DIVER. He easily could have said after we told him of the experience of the diver's on the boat that they shouldn't go that deep. These people were inexperienced that is the key. We were counting on him to keep us safe. If he doesn't then what is the point of having a DM? You might as well just rent tanks yourself and take your chances. They are there for your safety as well as a guide.
We are sorry for the loss of your friend.
If you - or anyone - has any doubts whatsoever about the competence of the staff, lack of planning/site orientation, sea conditions, depth regarding you/your buddies experience level, then DON'T MAKE THE DIVE!!! Got to a site that you are comfortable with - or simply cancel the dive.
It is our experience that many newly qualified divers often experience buoyancy control difficulties on dive sites where there is no visible bottom.
The final decision to dive rests with the diver - not the DM. However, as experienced DM's, our view is that good DM would have already assessed your group's skills and competence levels way before BEFORE you even set foot on the boat and selected an appropriate site for you all to dive safely.
Once in open water, you should dive responsibly in buddy pairs (minimum). Buddy pairing should be made clear to every diver AND slated on a board (pre-dive). And, there must always be a 'spotter' responsible person left on the dive boat (with full equipment ready if needs be).
Further, a DM has many roles and he/she should clarify his/her roles and responsibilities to divers. If he/she does not do this, then you should question their competence.
In our opinions, PADI DM training needs to be radically overhauled. All DM's ought to undergo a full internship with a proficient operator. There is no substitute for experience.
Without prejudice, it seems like there are many factors which led to this tragedy - including poor judgement, lack of experience, lack of planning and disregard of some basic dive safety procedures.
However, we think that it would be inappropriate to comment further/apportion blame at the moment as this case is now under official investigation.
[Mod - please note!]