Anyone who claims to understand extreme sleep deprivation and then says they still wouldn't resort to what this couple did can't have experienced TRUE deprivation.
Hallucinations of horrifying things. Inability to walk because your balance and spacial awareness is so severely effected. Vomiting. Migraines. Impaired judgement to the degree that you are incapable of even beginning to make a decision, literally being unable to comprehend the difference between up and down.
Depression so severe that you seriously consider killing yourself. Microsleeps that put you in danger of so many things that could kill you or your loved ones and yes, that's even just around the home!..
I've personally seen a man so far into sleep deprivation that he was eating a bowl of dirt for breakfast. After several days of no sleep he just scooped up a bowl of dirt instead of breaking open his museli package and started eating it with a spoon. We literally had to wrestle the bowl away from him and he was snarling like a demon and throwing punches the whole time.
After a good stretch of sleep later he didn't remember actually scooping up the dirt but he DID remember us taking it away from him and he was horrified because he admitted to us that had he been armed at the time he would have done his best to stab each and every one of us.
People who had his backs through thick and thin and were as close as his own family and he would have knifed us just to keep his bowl of dirt.
So folks, whilst I haven't done something like this myself (and hope never to have to) judge not lest ye be judged.
Without knowing exactly what they'd already done to try to mitigate this problem we can't claim to be experts on what they 'should' have done.