I would mind my business as I feel that is up to the individual who manages the personal trainers and the members on the gym floor.
I know it gets under your skin, however, I would leave that alone. Somehow I believe that situation is fraught with problems.
I would seek ways to create collaborative relationships with the staff as you never know how they might be of professional assistance to you.
I only interfere when it’s a questions of life or limb or when I am being asked for advice.
I try to tell myself that I do not know the other trainers’ goals, and I have sometimes told my clients to do an exercise differently from the beaten path with a very specific goal in mind.
But it still kills me sometimes to watch it. That’s why I pretty much exclusively work out at my own studio.
I posted a question similar to this a while back:
In this case as a guest…I would not feel obligated to correct the trainer or their client.
That’s a tough one. We do not know what the goal is, or the condition of the client which may prevent proper form.
My head would say to get on with my own workout and my heart would be crying out to ask if they would like some help…another reason I do my personal workout in private.