I don't see Toine as that big of a fall. In his personal life, Yes. Going from a multi millionaire to being broke is a big fall, but in his basketball career, not so much. Even after his best years he was still a big factor on the 2006 Heat title team at the age of 30. After that things didn't go so great for Antoine but his game wasn't meant to age well. He was an out of shape, 3 point chucking, no defense playing forward.
Did he fall off? Yes. But it wasn't near the fall that guys like McGrady and Iverson took. At least Antoine has a ring to show for it all.