I have to think that in a fast-moving situation like this, a capable physician - and with two billionaires fighting I'm sure they'd have someone really good - could work out a way to let them both die without technically doing anything that would be considered malpractice.
Or, just YOLO it and figure that no jury will convict you.
On a side note, i always hated how everybody is attacking the zuck for being weird while he's obviously on the spectrum. He may be evil and immoral but being very awkward isn't a choice he made. Same shit with Chris chan, the dude is extremely mentally instable, been bullied his entire life, blackmailed to do humiliating things, some on camera and emotionally abused by narcissistic psychopath and even the despicable act he committed was i believe suggested by the bullies that harassed him. What he did is sickening and unacceptable but he's still a mentally ill person and he's a much as victim. The dude needed to see a psychiatrist and administered heavy medications not become the literal toy of psychopaths.