Ah found it!
"Even his best friend, Lt. Claude Haegelen, (a 22 victory ace), was quoted as saying of Fonck:
He is not a truthful man. He is a tiresome braggart, and even a bore, but in the air, a slashing rapier, a steel blade tempered with unblemished courage and priceless skill. ... But afterwards he can't forget how he rescued you, nor let you forget it. He can almost make you wish he hadn't helped you in the first place."
