You're obviously, with your background, someone who knows more than most about situations of this kind.
Does the fact that the officer doesn't go to cuff the prone suspect after the kick/stamp potentially work against him from a legal/criminal perspective?
I appreciate there is the other suspect on the scene too (sat on the chairs with hands on his head I think?), but would a defence of ''I was worried he might take my weapon'' possibly fall apart due to him abandoning the suspect who he had just kicked/stamped on?
It's naturally hard to position yourself in such a powder keg moment, but I'd imagine that if an officer was concerned that a suspect might take their weapon, and such had the suspect subdued/restrained on the ground, they would take the opportunity to get some cuffs on at the first opportunity?