In his lifetime he appears to have been an especially esteemed musician, one of his obituaries calling him "supreme in his art, mighty in precedence and excellence".
Ó Cearbhaill also seems to have known John de Bermingham, 1st Earl of Louth, a member of a well-known Anglo-Irish family which had long been instrumental in the defense of the English control of Ireland.
However, Clyn reserved his grief for Ó Cearbhaill, writing that: In ista strage et eodem die Cam O'Kayrwill, famosus ille timpanista et cytharista, in arte sea fenix, ca pollens prerogativa et virtute, cum aliis tympanistis disciplulis djus circiter 20 ibidem occubuit.
Iste ... vocatus Cam O'Kayrwyll, quia luscus erat nec habebat oculos rectos, sed oblique respiciens, et si non fuerat artis musice cordalis primus inventor, omnium tamen predcessorum et precedentium ipsum, ac contemporaneorum, corrector, doctor et director extitit.
He was called Cam Ó Cearbhaill because he was one-eyed and could not see straight, but looked obliquely; and, if he was not the first inventor of the art of string music, all his predecessors and precursors, he was corrector, scholar and director.