I'd say because he couldn't. In any rescue there may be a point where the rescuer has to decide whether there will be one or two victims. Read the
@MaxBottomtime post, above, again.
On a dive such as this I will tell my buddy, if I have one, to insure they will be able to surface safely after a rescue before they start, and as it progresses. I don't want to die, or I may be dead already, however I certainly don't want to take an innocent bystander, or worse yet a friend, with me. This is one reason I usually solo for more advanced dives.
That's a lot of dives on your profile not to understand the situation.
Bob
I'm with you Bob DBF;
I prefer solo diving, except when my sons are in the water, then I am just leading the compass course and
keeping an eye on the lads.
A friend, a very experienced diver lost his buddy on a dive on the Andria Doria.
The lost diver went into the ship in an attempt to find some ships China.
My friend stayed outside the sunken vessel.
His buddy never came out. So, he surfaced, taking his decompression stops
and informed the boat crew.
They found the lost diver entangled inside the ship.
I am learning quite a bit on this thread.
I have a fair amount of CA dive experience, both shore and boat diving.
Never been diving on the offshore oil rigs.
What I have learned, so far, is that I would want a good experienced diver as
a partner on such a dive. I do not think a oil rig dive would be a wise choice for
a solo dive-at least for me.