How would you feel getting close to someone in a confined space (remember the first day?), thinking you've bonded and then find they nominate you face to face over smoking!
He has every right to feel betrayed by John. Why else are the crowd baying for John to be out??
However, Darren must be a bit dim i.e. after he (again) confronts John about being hurt, - clearly wanting John to feel bad except the barstard doesn't have a conscience - only then to go along with the duping of "we're cool aren't we?" What part of being badly hurt is cool????