On top of this, Brynn had problems with Phil Hartman years before Andy gave her the drugs. I remember Phil was angry at him for giving her drugs because he was tired of it, but I don't recall him ever blaming Andy.
Honestly, Brynn was fighting with Phil for a long time, in his time on SNL and Newsradio. They even used to get in fights backstage, mostly on Brynn's end. She was also a psycho who threatened Phil's ex-wife for sending them a congratulations card when their child was born.
She was unhappy that Phil had a career and she wasn't famous and their marriage was mostly horrible. I'm pretty sure Phil married her for looks mostly and because he didn't think he could get better. (Based on what I read about him anyway.)
That said though, Andy Dick truly is a shitty person and deserved to get beat up by Lovitz.