I mean, the movie takes place over the course of 3 or 4 days, right? Nick had injuries to his spinal cord and sternum, a fractured clavicle, a perforated lung, and a terrible headache. But he comes in all:
“Ain’t no thang. Let’s fuck up these HYDRA bastards.”
Okay, here the thing tho. Given he was piloting that helicopter with a great deal of skill at the time… probably not many pain killers were involved.
Which means he was in a SHIT TON of pain here but still got the fucking job done. If that’s not bad ass, I don’t know what is.