re: Smoker is rolling

Hey Fellas, got a question I need some input on. I smoked a chicken this last Sunday, and while the meat was solid, the skin was really rubbery to the point it was inedible. I haven't had that issue before, and think I might have a few guesses as to what caused it, but curious if others have experienced this before. A couple specifics on the smoke to help inform any responses.

- I brined it longer than I usually do...it was in there for almost two days (thought I might smoke it for football on saturday, but didn't until Sunday)

- I ran it at about 260 for most of the smoke, but cranked it up to about 325 for the last hour to get it to temp and hopefully crisp the skin

- Total smoke was almost 5 hours, but I pulled it off at 158 because it had taken longer than I expected and we were hungry

- When I smoked a brisket this last time, I left the vent open (I have a gas masterbuilt vertical smoker) because I read that the airflow will help the bark. I left that vent open for the smoking of the chicken

Here's a pic. As you can see the meat is nice and juicy, but the skin is darker than I've seen in chickens I've done before. So I'm really thinking that either the vents being open, the length of the smoke, or the length of the brine might be the culprit. Or I just got a shitty chicken.

Thoughts?

(the line across the breast is from twine I used to tie the wings in tight so they didn't overcook)