Kurt Angle left WWE in 2006 and returned to the company only in 2017. Around the time of his departure from the company, he was addicted to painkillers (and had a severe neck problem) and was in dire need of help. But he was such an asset to the company that WWE had a hard time letting him go. In fact, during his interview with Chris Van Vliet, he revealed that Vince McMahon almost fought him when he asked to be released.
In the interview, Angle said that he and McMahon didn't part on good terms and the two didn't speak for eleven years after he left WWE and reconciled only when he made his comeback. He added that he's always considered McMahon to be a father figure to him.
Delving into the details, The American Hero said that when he announced his decision to quit in 2006 in a meeting, McMahon pulled out a series of pages that had detailed threats from Angle, something that the latter didn't remember doing as he was high on painkillers and somas. He recalled:
"He pulls out 5 typed pages of text messages and phone call messages I left him. And I'm reading it and it says, 'Vince, I'm gonna beat the $h#t out of you when I see you. Vince, you better answer the call or I'm gonna kick your a**.' Really, really crazy stuff. At the time, unfortunately, I was taking painkillers and somas and every once in a while, I would blackout."
"And he (Vince) stood up and he took his jacket off and said, 'You want to kick my a**, let's go right now.' And I looked at him, my God, I can't believe Vince McMahon wants to beat my a**. This guy has been my father figure for 7 years and I have too much respect for him to stand up but he wanted to go."
He revealed that he then left the room and broke down.
The great Kurt Angle's request for a release was eventually accepted and he left the company and went on to sign a contract with Total Nonstop Action (TNA) wrestling. Upon his comeback in 2017, he was inducted into the WWE Hall of Fame and had his last match against Baron Corbin at WrestleMania 35 (in a losing cause).
We just asked The Shockmaster about Vince McMahon's retirement here