Some say it isnt Bruce Randall.
That doesn't mean it is not Bruce Randall, as they think it may be Bill Clark.
I thought and still feel it is Bruce Randall.
Here's Bruce Randall with a very enthusiastic "friend":
The appearance of the man in the following picture does resemble Bruce Randall.:
It is also possible that Bruce Randall may have worn a shirt that said "Clark's Gym" on it in order to support his friend Bill Clark's gym. Of course, the logo on the shirt increases the chances that the man in the picture is Bill Clark considerably, but that doesn't rule out the possibility that it is someone
supporting Clark's Gym that happens to be utilizing such movement. Now...
Look at the background. Peg board on the wall with tools hanging from it, hanging florescent lights above a work bench, a beat up (dirty?) cabinet... The location appears to be a
garage, not a gym.
That is a squat rack to his right as well, and he's utilizing a dipping belt in order to complete the hip lift movement. It appears as if he has hooked the dipping belt up to a chain which goes around the middle part of the loaded barbell, enabling him to lift the barbell off the floor.