The thing is, as we saw in the Copterline accident, if the servo goes to full extension/retraction the ride will be so wild and disorientating for all concerned that normal CRM will probably be thrown out the window as well. If one of the pilots has the presence of mind to switch off a servo, and then the other one if that didn't work, might actually save the day for them. Attempting to run a challenge/response emergency checklist by the book, when one pilot head is probably crunched hard up against a windshield pillar, and the other pilot head probably stretched on its neck not far away from the same windshield pillar also, and their adrenaline level and heart rates are immediately shot through the roof, to expect a vanilla dose of by-the-book CRM in these circumstances is fanciful.
One of the 2 pilots needs to have the presence of mind to take decisive action. The action needs to be announced, if possible; the circumstances do not lend themselves to a timely discussion of the matter.
I consistently see problematic CRM in a normal environment when there are relatively minor malfunctions to contend with, let alone when the helicopter is playing rollercoaster and trying to throw you out the door. This is the reality I'm afraid. An action taken that is not by the book but which saves the aircraft is a better outcome than a crew following a checklist perfectly all the way to the scene of the accident.