"busted both his legs" just means that he broke them. I think it's probably more figurative than about someone literally jumping out of the 2nd story window.

Jimmy Shoes is Jimmy Iovine's nickname, btw. And if that's meaningless to you, Jimmy Iovine is a producer and is on the Special Olympics committee with Jon. He's produced the A Very Special Christmas CDs and several specials including the Concert for New York after the terrorist attacks on 09-11. Jon was the first person he called when organizing the line up.

Becky