Either way he is duty bound to follow the QRH drill or suffer the consequences of a subsequent legal case should his attempts at survival be only partially successful and passengers die as a result.
Every Authority I have flown under has always had a nice Escape Clause written into the Regulations.
For the FAA it is as follows:
§91.3 Responsibility and authority of the pilot in command.
(a) The pilot in command of an aircraft is directly responsible for, and is the final authority as to, the operation of that aircraft.
(b) In an in-flight emergency requiring immediate action, the pilot in command may deviate from any rule of this part to the extent required to meet that emergency.
(c) Each pilot in command who deviates from a rule under paragraph (b) of this section shall, upon the request of the Administrator, send a written report of that deviation to the Administrator.
Now however one wishes to argue it.....when I am the PIC and I have to make a decision or set of decisions that directly affect the safety of the Aircraft, my Passengers, Me, and people on the Ground....I call the Shots based upon my best training, experience, and knowledge of the factors I have to draw upon.
The Checklist is a piece of Paper written by folks seeking to cover their own Ass and is massaged by Lawyers.
Their interest is not necessarily coincidental with yours as the PIC if for no other reason their Ass is sat in a comfy chair in some fancy office somewhere and not in the Cockpit with you.
Refer to Sasless Rule One: "Ass, Tin, Ticket!".
Do what is best for what is setting on your Wallet and generally you will do right.
If you have to use up that Airframe to protect what is setting on your Wallet...the Boss can replace that machine.....and if the Authority doesn't like you decision and you are there to see them take your License.....you can take up Transcontinental Truck Driving for the time you are out of the Cockpit.
Fire Warning Systems in Helicopters are not renown for their infallibility particularly with secondary indications of Fire.
In the situation described....over mountains obscured by Cloud...and a for real fire that will not go out even after all the drills are done....well sometimes Fate smacks you right between the Eyes.