In his prime, I'd imagine he could have perhaps done a legit paused press (in competition) in the mid-600s.
The video above of him hitting 680 isn't paused in any way and is assisted GREATLY by the considerable compression off his chest. Not to mention the bar is almost stalling when the spotter grabs the bar, and he's still not near a full lock-out.
I am not trashing on his benching prowess here. Just keeping it real.