Aircraft wasn't doing what he wanted? That's a joke. It exactly did what he asked. If he didn't know how to ask then it's his fault. It's mentioned in his earlier checks that he has a habit to select something in a hurry. Click, click doesn't work unless you know what is happening and what you want to do. A/C is diving, thrust has hit climb, speed is increasing, you don't know what to do with AP. OK slam the thrust closed, knock the AP off and level off.
I also fault Airbus for the thrust lever design. Had they been “conventional”, the whole bit with thrust lock then climb wouldn’t have been a factor.
But then it wouldn't be called Airbus but perhaps B MAX. Boeing is conventional but still they crashed it in SFO, nobody had any idea what conventional ATHR was doing, another in Dubai go around they had no idea what they needed to do for touch down GA. NTSB, FAA asked Boeing to have look at thrust hold. They will keep looking but aren't going to do anything. Pilot flying has to learn and remember.
Look Airbus is Airbus it's easy but definitely different. Guy who transitions on to it has to learn about it. What ATHR does or doesn't is not a secret it's there in the manual, it's taught. What about the PM why didn't he do something? Perhaps he also had no idea. This is the problem with CRM. Unless copilot is well trained he is not going to overrule the more experienced captain. There was only one problem the capt didn't know how to cancel EXPED, period. Had he pulled any FCU button the flight would have ended without any excitement.