For all the non-pilots reading, hopefully of use........
There's and enourmous difference, in terms of skill and decision-making ability/experience, between the brand new F/O as opposed to the experienced F/O waiting for the next command vacancy.
There can be an enourmous difference between operating an aircraft with many carried-forward defects and operating one with no defects.
There's an enourmous difference between operating an aircraft into difficult airfields in bad weather and operating into easy airfields in good weather.
There's an enourmous difference in the workload between different aircraft types.
There's an enourmous difference in the cabin crew's ability from one to the next.
Starting with the assumption that the Captain is incapacitated, work out your own combination. You could, possibly, dream up a non-event or, alternatively, a script for an "interesting" movie !
If the F/O in question had the worst of all of the above, then I congratulate him/her.
(PS - I strongly agree with Budgie69's comments regarding line training flights, but that's just IMHO.)