The surviving diver is a close friend of mine. He is fine, and should be back in the states by now.
There is a lot of speculation going on here, most of which is incorrect, and I won't get too detailed with it.
Basically this, the survivor was diving his plan of 160. He's trained TDI Full Trimix. He knows what he is doing, and he is the type of guy who does not deviate a dive plan, even to look at a pretty fish. There is a possibility he wasn't diving with them, and wasn't aware of what went down until he surfaced.
The other two, well, one of them belongs to a crew of divers who are known to dive "Questionably". I will try not to talk ill of the dead, but he has been doing this for a while, and it looks like he took someone who had never gone that deep with him (This is my bit of speculation). I don't think his buddy had ever seen past 130, but don't quote me on that, I don't really know the third guy so well.
One diver made it back to the deck, and described what happened before suffering from Cardiac arrest in transit (Possibly due to Fizzing out). The description was that they got split up, and when he saw his buddy, he was at 250-255 lying on his back. There was more than likely a medical issue at depth.
At some point this diver may have ran out of gas and/or corked.
I've heard rumor they found the other body this AM, however I have not confirmed it, and my friend has been on the road just trying to get home.
That's the latest and most accurate. Out of respect for my friend, I've told you most of what he's told me, and will not reveal names. There will be an official report about it later, but for now, just know that, yes, there were questionable actions being taken here, and they paid for it. No need to blast them on a thread (not saying anyone is) .
Thanks,
D