I'd say Gil was just passing by while Anders was throwing up, and that he didn't know anything about his father.
(I didn't quite understand what you wrote, so this comment is based on what I understood XD)
Ohh thanks. I think you got my message just right since I understand your answer. I really do hope he isn't part of it. It's because as far as I know, his place is far from his and I think when going home, Gil doesn't pass by Ander's house. Or maybe I got my information wrong and I might need to read the story routes again.
Also sorry if my statement was confusing hahahhaha. My bad 😅