As a rule, I never permitted a client to chamber a round until it was absolutely necessary - as in stationary right beside me or in front of me. But then, that was only in grizzly country, not really dangerous game, most of the time.

Having one of them walking/stalking behind me with a loaded rifle was not a risk I was willing to take with 9 out of 10 hunters.

I have not guided very many hunters in total, however only 2 out of the bunch were proficient & experienced enough hunters themselves to be allowed a loaded rifle, where I could then concentrate on the task at hand, rather than the direction their muzzles were pointed.

Even with an unloaded rifle, most of them would unconsciously slip a finger inside the trigger guard - imagine those trusted with a round in the chamber - and they are behind you - highly excited, clumbsy and ill-trained.

Of course, no one here would do that, but you understand the caution necessary.