He said in the r/Powerlifting daily thread when it happened that it was a Troy barbell. Glad he was able to walk away from that.
It would have been ugly if he failed at the bottom. The safeties were barely above knee height. Unless the bar bent enough to touch them.
That barbell didn't even survive the walkout before it started bending.
I wouldn't rate that barbell at 675. A maximum safe load should be at least 1/2 the yield strength.
Yes, if he lost it in the hole he would have been forced to dump it, a wreck compared to setting it down on properly adjusted pin/pipe.
Once he was standing with an unrackable bar, there were few options, hooking one side and bailing was less of a wreck than dropping 675 from shoulder height.
He was planning a triple, so once he stood back up and realized the bar had failed and it wouldn't meet the hooks,he could've squatted back down and dumped the bar on the safeties. Less risk of injury that way, and the bar was already scrap metal. I guess some risk of damage to the safeties depending on how far the bar fell, but metal is replaceable, injuries are bad.
There were a lot of things that could've gone even worse here. The bar might've slipped off the one hook he got it on (or the hook might've failed), one of the clamps might've slipped off, or the bar might've snapped. He was lucky to get out of that with just a knee-tweak.