Exceeding limits on SAR
Re the RN SAR scenario, we just don't know what happened. Hopefully, if it happened, the reason we know is because the crew came home and owned up.
In extremis, potentially trashing an aircraft, and risking the crew, can be justifiable but the captain had better be prepared to stand up and explain himself whatever the outcome. From personal experience, senior officers with a fixed-wing background, who may see SAR as rather peripheral, are unlikely to understand or be sympathetic.
I took a SK into a situation some would not approached and came away with people who would otherwise have died (smiles all round) but the aircraft was badly damaged in the process. This did not involve exceeding limits (unless of natural caution!) but the implications are similar and the evidence more obvious. I would put this alongside battle damage as "what can happen when you take calculated risks to complete missions" Again, being honest and being able to justify it afterwards is all important.
OBTW, the whole crew discussed the risks in advance and agreed with the plan so let's drop this chip-on-shoulder line about medal-hunting, two-winged master race etc. blah, blah.
As for exceeding aircraft limits, this is not to be lightly undertaken. As for guessing what the designers factored in, forget it. Especially with helicopters, its is an imprecise art and aircrew should treat limits with respect. If it happens, minimise it, get the aircraft back in the hands of the engineers asap, own up and hope it doesn't fall appart two flights later with your mates aboard.