Ahhhh, I believe that's what we in the biz call a good old fashioned oopsie daisies. It happens to the best of us out there. One second you're trying to give the starting quarterback of the multi-billion dollar franchise a little pain-killer shot, the next thing you know you have ruined his entire season.
According to a quick Google search, a punctured lung takes 6-8 weeks to recover from. This dude seriously CANNOT catch a break. He was good in Buffalo, got replaced. Went to Cleveland, they drafted Baker. Sat behind Phillip Rivers last year, earned the starting job, and boom, punctured lung.
As for the doctor, well, gotta give him the boot. Doesn't matter if he's the best doctor on the planet, no player is ever going to trust that guy again.