The movie was excellent, also, and I'll rewatch it as soon as I finish the book. It's streaming on Amazon prime.
The factual mistakes in the other book are annoying, but so far not enough to make me stop. There have been books I've stopped reading after either too many factual errors or something so huge that it undermines the author's credibility. The one example that comes to mind was (and I no longer recall the title) one in which the author incorrectly stated that Margaret Mitchell had shopped around Gone With The Wind to numerous publishers before MacMillan accepted it. Not true. A MacMillan editor was the first person to see it. In that case I fired off an email to the author, and he eventually responded. A bit later there was some other error, just as bad, although I no longer recall what it was and so I stopped reading.
Historical fiction can be a bit dicey with me. I'm willing to allow a certain amount of license, although if it's something I know enough about, I won't keep on reading if they get too much stuff wrong. The essential and underlying problem in a lot of historical fiction is that the characters are simply modern people dressed in old clothes. They really were different in essential ways, especially in attitudes and beliefs, that shouldn't be ignored and glossed over.
(Climbs down off soapbox and puts it back in the closet)