An interesting opinion, and keen to hear more of your experiences.
My own would indicate that shooting and killing a buff or ele because you perceive them as a threat even though you dont have one on quota, and or the PH doesnt have any left on quota for his concession, and in some countries such as Zambia ele is on the non shoot list, you're going to have a lot of explaining to do to the relevant wildlife authorities.
Zimbos might have the leeway of writing eles off as "non trophy" but others dont have that luxury.

I havent been keeping tabs on PH deaths for very long but I believe the fatalities in the last 12 months have been due to an elephant, whilst hunting elephant, and by anti poaching patrol.
If we go back a few years there have been a number of PHs / trackers getting shot in the back by clients armed with DG rifles on DG follow ups, from memory 1 incident was on a cat hunt, not sure about the others. Hard to say if lack of familiarity with the rifle they were carrying was a factor at play but it does spring to mind.

I'm not advocating taking your deer rifle, donning a pith helmet with matching white linen suit and leaving all situational awareness in the hands of your PH, but you dont need a 300g bullet when a 150g create a better wound canal given the low resistance it will meet in the flesh of smaller PG. Take the rifle you are familiar with and able to get onto target and on sticks as fast as possible. After all a shot in the air from a deer rifle will probably have the same ability to change the mind of recalcitrant DG, just dont tell the ele your bluffing

Of course you could take two rifles, and then constantly worry which one you left on the truck, a problem that can be overcome by never venturing far from the truck....