Every captain who lost a ship in those days faced a court martial. Standard procedure in the British Navy. Courts martial were intended to gather all relevant information about an incident, which is normal in the military when any reverse is suffered. It does not necessarily indicate guilt on the part of the commander who is being courtmartialed, it simply indicates an inquiry to establish whether or NOT he did his duty as he should. There are many circumstances in which a captain can still perform admirably, do his duty to the utmost, and lose his ship anyway. Captain Pearson performed his duties very well on that day, and he was exonerated.

As to whether he was "a sore loser"...I doubt that anyone enjoys losing his own ship.