If the climb to F450 and then the erratic descent to ~F230 is true, it looks awfully like someone was at the controls who was finding that the real thing wasn't quite the same as Flight Sim. and it took him a while to get his head around handling it.
Everything I've seen suggests that F450 would at best have been nearly impossible - and the rapid descent WOULD have been impossible. That said, if there was a climb to anything approaching that altitude, I suspect it was done to eliminate opposition from the cabin. From what has been posted, the drop down oxygen masks are useless at that altitude.