a well trained careful pilot who unfortunately finds themselves in a sufficiently high workload situation to mishandle the aircraft,
Ah, and this is a reminder to one of the most basic rules: "Aviate, Navigate, Communicate". It's up to the careful pilot to always prioritize, so that keeping the plane flying safely, and thereafter toward a safe place to fly are the priorities. If other high workload aspects present themselves, they must be prioritized out, until the pilot's capacity can accommodate them. 'Worst case, after you land, you're writing a report explaining why you failed to communicate with ATC.
I've trained pilots, who, when I introduced a failure, simply stopped flying the plane. A few times, I have been stunned to see the plane simply continuing on an unintended path uncorrected. One pilot, who I was training in his newly purchased Bellanca Viking very simply could not manage and prioritize more than one thing at a time. If I introduced even the smallest distraction, the plane was flying itself. After 19 hours of type training on the Viking, I declined to provide him a checkout letter. A delightfully nice fellow, but he just did not have what it took for a high performance single.