I honestly don't know what to think about J. Randall Taraborelli. The only book of his I ever attempted to read was his updated biopic on Michael, and I couldn't even get more than a few pages in. I don't think my reaction was due to him being an inherently bad writer, but if you're writing about someone as legendary as Michael Jackson, then you need to be engaging from the start, and stay that way through the whole book. I've seen some interviews with him, and he seems like a nice enough and respectful guy, but since I don't know him personally I can't really go any further than that. I have read about several people accusing him of purposely lying in his books, or embellishing to make what he writes sell better. This is a direct quote that I found, on an archived page from the online blog Gawker, where Mr. Taraborelli talks about his biography on Beyoncé Knowles...
"I decided a long time ago that it was my responsibility as a biographer to invade a person’s privacy. Once you cross that threshold, you're good to go. But I also know that she—I have to say, stroking my own ego—she’s so lucky to have me as a biographer. I’m sorry, it’s just the case. I know what I put into my work. I know what my standards are, and I know what the options are in terms of other people who might have written about her. I’m the first guy to do this, to really unpack her life. And I’m doing for her what I did with Michael Jackson. Diana Ross, Michael Jackson, and Beyoncé were completely new terrain prior to my tackling those subjects. It sounds terrible for me to say that she’s lucky that I’m her biographer, but what I’m trying to say to you is that she could do a lot worse. I really care."
His Wikipedia page also contains this quote...
"I think as you get older as a writer, your standards change. When I was a kid, my standard was very simple: If it was true, I put it in my book. That was it. There was no wiggle room to that. I’ve been through enough in my lifetime to realize there has to be more of a standard in biography than just the truth. There has to be an eye toward empathy. There has to be an eye toward understanding interpretation. There’s a lot of nuance that goes into a biography that is bigger than whether or not something is true. When I was a kid, it was a simpler time. Today, I weigh everything on a moral compass. It has to do with: Is it fair? Is it hurtful? Is it going to cause people pain? That’s a big part of my process today that when I was a kid, I never considered."
So at the very least, this guy comes off as somewhat egotistical, and possibly too compromising for my personal taste...but that doesn't make him a liar.