One important thing to note, disregarding the realism argument for now. The party is not Hercules and Friends.
The party has capabilities equivalent to Hercules traveling with Merlin, Jesus and Loki at once. So yes, Hercules would be able to survive getting stomped like that, Jesus would heal him and then he'd go back in to sneak attack the bastard with Loki while Merlin rains down fireballs. That's playing as the designers intended, not even playing as optimised.
To be fair, it almost is Hercules and friends. The monk is a good tank and scores crits of over 100pts at level 8. I'm the healer, I stay invisible with my ring of invisibility and cower behind my sanctuary. I pump tons of positive energy into the tank to keep him alive. Just the two of us make a mess of all planned encounters and the DM is frustrated. There is no Merlin or Loki. It's invisible Jesus and Hercules (Though, we just had a 3rd player join us. He is nowhere near the optimization level that we put into our characters) and the enemies only see Hercules.
I had a talk with the DM (I didn't mention the surgeon idea, just yet). As a DM myself, I feel his frustration (the Monk's player plays a barbarian in my campaign, also scoring 300+ crits, ruining my encounters). I started discussing alternative tactics against the Monk. Simple spells like grease, entangle, confusion, etc will make him less effective. He is just one person after all, and if you overwhelm him with 10+ smaller monsters that grapple, trip, etc. he won't be able to compensate. He seemed receptive to the idea and going forward he might rethink his tactics.
Tell your GM to allow the cut open and torch it with postive energy, or tell him plan B is killing the Monk and rezzing him.
This idea actually came to mind. But as a LG character, it would be against my ethos. I would need to be atoned.
UPDATE: I talked to the DM. He was keen on the surgery idea. He will make a chart of things that can go wrong in surgery (ie. cutting an artery, infection, etc) and allow me to use a combination of skills and spells to get through it. Huzzah.