I took the "religious slant" as the pilot saw the signs that God was trying to save him during this process and he ignored them. He could have change when he met the red head chick, he could have changed when he met the other pilot and his wife but he didn't. He coud have changed at any point. It took him to get to his lowest point, drinking up all the alcohol in that room and having his lover take the blame to cover his ass.
I thought, he thought he was a hero during the whole flight mishap and shouldn't have been blamed. Then the airline execs had to protect his ass to save them from lawsuits and such, so this bolstered that "I didn't do anything wrong mentality".