I didn't think the video was overly negative, I seem to remember back in the day there was a lot of fuss about the DeLorean deal and after all Fred Bushell did go to jail over it so something must have been odd about it. For me it lined up pretty much what I think about the guy - brilliant but a bit dodgy, someone I'd happily share a beer with but not ask round to my house for dinner.
In the 70s & 80s I was in Club Lotus which back then was basically Graham Arnold's enterprise and he'd usually attend several events through the year. A very talkative guy and certainly a salesman for himself, he'd tell some interesting tales about his days at Lotus and the on-off relationship he had. Were they true or was it the late night beer ? who knows, but Chapman certainly came across as "colourful".
Brian