When I was MUCH younger and inexperienced I was that guy on occasion... one time this gentleman scolded me in French in the common area... all I could understand was his miming of bag rustling in a mean way. I got defensive and immaturely responded with a huge snore pointing back at him. I saw that guy everyday for the next 3 weeks.
I'd suggest, as a public service effort, if you see him again, and there is no language barrier, you cheerfully approach him and say something like this...
"I remember you. We stayed in Zarautz together. You like to get a very early start... I admire that. Sometimes I do too but I also like to sleep a little later on occasion. When I want to leave especially early I prepare as much as possible the night before, and anything I have to do in the morning I do outside of the bedroom in the hallway or the common area, so as to not disturb the other pilgrims as much as possible."
He may just not realize. Theoretically it may have been his 2nd or 3rd night ever on the camino,