that isnt true at all!
no one drops the bar onto the blocks during SGHP's. you catch it on your thighs and lower it to the blocks/bench whatever -atleast thats what 99% of people i train with do.
so the only reaction force is when the bar is just resting on the bench, before you pick it up.
so damage to bar is a factor of the application of reaction force from the bench. since the bench/bar isnt moving, it IS the same as a sumo deadlift grip on the bar.
damage to the bench is exactly the same. since the bar isnt moving, its the same as sitting on it, holding weight in some form (military press etc).
i don't know anyone that drops the bar onto supports. (maybe the last inch or so)
lastly, i didn't criticise anyone. i reassured him that the bench and bar would not be damaged. -i literally NEVER criticise anyone unless its constructive/i can offer advice.