What happens to Phil that requires the guys to take him to the hospital to receive treatment for a concussion and some bruised ribs?
BEST EXPLANATION: It’s a plot device that let’s the doctor—when the guys visit him again—share some more details from their previous night’s adventures.
But it is referenced in a throwaway line at the end of the movie. As best as we can determine from the incriminating snapshots that run with the end credits, Phil (Bradley Cooper) probably suffered those injuries while defending Stu (Ed Helms) from an enraged Wayne Newton.
[youtube=http://www.youtube.com/watch?v=UlrdVRISrS8]