Maybe so. Except in cases of rescue, quoting SAR spokespeople, SAR tends to err on the side of the rescued, after all most really do need the help, they're glad to give it, risking their lives etc. And here, the person with a broken leg probably needed help. Not so much his friends evidently. I'm struggling to find a reason for three to descend while leaving your friend alone with a broken leg on a glacier - was he the only one experienced in snow travel, did he have the only bivvy, the only sleeping bag, would he have stayed comfortable through the night, the others ill prepared for it? Were they equipped to dig a trench or snow cave for warmth? Its hard, if I put myself in their place I stay with poor Harvey through the night, and improvise a shared shelter, but I'm not a climber any more and tend to carry enough on a mountain for that kind of stuff. Clearing a snow cave for four would be pretty tough if all you had were ice axes, but digging down shouldn't be too much of a bother, and waiting for dawn in your bivy sack.