He's a laiaaar :cry:
He's not as acrobatic as people make him out to be that's when a stuntman comes in his place (back in the day it was mostly his buddy Yuen Biao who is the REAL acrobat of the Chan - Hung - Biao team). He did however do all the stunts shown in the outtakes but many were just too risky physically I guess (but that fall from the clockt tower, that he did by himself... :?)
Like, I remember some scene from, um, Drunken Master, I think, when he's bending faaaar back, dat was Biao for example.