Only two months ago one of our senior 1st Officers blew an upgrade c/ride for simply failing to react correctly to an upset.
Not knowing the facts of the case of course but maybe his training was faulty? Much depends on the ability of the simulator instructor to first hop in the seat and actually demonstrate a recovery. Few instructors risk their reputation by daring to demonstrate in the simulate lest they themselves stuff up. . Most just shout and criticise from the safety of the jump seat at the back of the sim. That is not instruction. I have observed many pilots in the sim that had no idea how to recover safely from a UA. Back in de-briefing with a nice cup of coffee in the hand, it usually turns out they have never been taught how to recover. There are many airline operators out there that simply do not believe in UA training - or it might be treated as a last minute "fun" exercise, if time permits.