One simply don’t hang up with rebels on an ice planet performing patrols for fun. Hanging around with rebels is not like being in a social club. You don’t simply associate yourself with people who are being perceived by the Empire as worst-than-criminals just to hang around with “friends”.
Where is that stated in the script? Isn’t this also just an interpretation based on your impression? Or is your impression above everyone else’s?
Yes the above was my impression that I added to the things that are already “crystal clear”, i.e. that he joined the rebels (see the part of my post you cut out). He is there with the rebels, performs the patrols, wears rebel insignia, reports to the General, General expresses his regret to loose a fighter like him, etc. All this is explicitly in the script and in the film.