In an excerpt from his new book, "Out of the Rough," posted on the New Zealand website stuff.co.nz, Williams describes Woods' unusual behavior immediately before his 2009 sex scandal, and then goes on to express his indignation with the media, Tiger's management team, and finally Woods, himself, as the scandal unfolded.
Williams says he was first alerted to a media story involving Woods' relationship with nightclub manager Rachel Uchitel while he and Woods were at the Australian Masters in November of that year, as Woods was exhibiting uncharacteristic and "strange" behavior, appearing to party all night and almost showing up late to the golf course.
After Woods won the tournament, Williams writes: "As I was driving, I got a text from Mark Steinberg which read, 'There is a story coming out tomorrow. Absolutely no truth to it. Don't speak to anybody.'
"In the back of my mind, one thought often replayed, over and over, without an answer: What did Tiger do with himself to get rid of the stress that built up in his life?"
Williams said it was easy not to answer any questions about the story because no one asked - until, of course, Woods' infamous fire hydrant accident a short time later on Thanksgiving.
"A few days later, in late November, he emailed to say that he was in a spot of bother and would be in touch," Williams writes. "I didn't hear from him again for four months."
Williams, who denies any knowledge of Woods' extramarital affairs at the time, says he "repeatedly asked for Tiger's management to release a statement that would clear me of any involvement in this lurid news," but that they would not do so, as publicly exonerating one member of Tiger's inner circle might make others looks culpable.
"How could I spend so much time with him and not have an inkling this was going on?" Williams writes. "The answer, in a roundabout way, is that Elin didn't know either. Only a handful of his oldest buddies actually had any idea this was going on. I didn't know because Tiger didn't dare tell me."
Feeling "angry, frustrated and hung out to dry," Williams proceeds in the excerpt to criticize Woods' public apology in February, including a quote from Ernie Els, who called Woods' decision to hold a press conference during a tournament "selfish."
As for Williams' own reaction: "That was way over the top. It was a peculiar thing to watch too, as he was so awkward in his delivery and choice of words. I turned off the TV thinking, 'That's not the Tiger I know.' It was heavily scripted with nothing natural about it."
Following a phone call from Tiger in March, during which he says Woods was "apologetic" to both him and his wife Kristy, Williams writes that he had a face-to-face with Woods later on to air his grievances.
"I told him it was something that could have been avoided and how bitterly disappointed I was at his people for their total lack of communication and unwillingness to put out a statement saying I had nothing to do with it. I was adamant that some of his behaviour on the course had to change. ...
"One thing that really pissed me off was how he would flippantly toss a club in the general direction of the bag, expecting me to go over and pick it up. I felt uneasy about bending down to pick up his discarded club – it was like I was his slave. The other thing that disgusted me was his habit of spitting at the hole if he missed a putt. Tiger listened to what I had to say, the air was cleared and we got on with it – his goal was to be the best player in history and my goal was to keep working as best I could to help make that happen."
Just a few months later, in July, Woods would announce that he and Williams were splitting up after 11 years as a tandem.
Williams' book will be released Monday, Nov. 2.