Mann was extremely athletic and Haygarth recounts how he "could cover an immense deal of ground, darting about like lightning".
He could also perform extraordinary feats of agility on horseback, being able to pick up handkerchiefs from the ground while going at full speed.
Haygarth recounts that: "he had been out shooting, and on his return to the Half Moon Inn, at Northchapel, wet and tired, he had a free carouse with his companions; refusing to go to bed, he persisted in sleeping all night in his chair in front of the fire.
It was and still is the custom in that part of the country to heap together all the ashes on the hearth, for the purpose of keeping the fire in till the next day.
During the night, having fallen asleep, the sparks ignited his clothes (or, as stated in Nyren's book, he fell upon the embers), and he was so severely burnt that he died the next day, not surviving twenty-four hours.