Possible distraction scenario
Pre-flight aircraft log check not thorough.
In climb out Wx avoidance taking a lot of attention.
Insidious slow thrust reduction goes unnoticed while radar and outside conditions being checked and heading changed.
Further climb clearance given and set.
Possible further distraction if cc rings
Neither pilot monitoring engine panel or control positions.
Too little attention being applied to basic flight conditions.
Suddenly all hell let loose - AP off - sharp roll - loss of height - one engine in idle. Change of attention. Change of priorities. Confusion.
All just an imaginary scenario to demonstrate possible distractions - not intended to accuse or condone the crew in the actual cockpit conditions, which we don’t know.