Years ago I had hired a professional genealogist in Scotland. I had given him family information but also information from the IGI (which I thought was legit). I hadn't referenced the IGI and he said, in essence 'Where are you getting this stuff?!". When I told him the IGI he said that was stock-full of so many errors - he said never, ever use that as fact.
He was quite right! (I could almost hear him yelling all the way over from Scotland).