All of Ray's history with Sabbath was weird as hell, and he came just at the wrong time.
Sabbath was basically - and unofficially - done, Tony Iommi wanted to do a solo album and so he got Glenn Hughes, but he was forced to call it a Sabbath album and Glenn - in a not so excellent moment of his life - wasn't up for that.
He had to fire Glenn Huges in the middle of a tour, he hired Ray Gillen who just happened to pass by basically, ended the tour with him, and then the Eternal Idol album got stuck in the musical equivalent of development hell, with a lot of band members coming and going, to the point that Ray got fed up and left as well.
Definitively being in the right place, but at the wrong time.