That is not at all what Julian suggested.
You're quite right, Julian's business model was weaker, it didn't have the sales element, and it takes the gall of an ex-Assistant Chief Constable to try to imply Police approval.
I was thinking more along the lines of public service than business, although obviously nobody can work for free.
I'm not sure about the policewitness.com thing at all: it implies police approval and there are
a) a minority of lunatics who will actually attack anyone they think is working for the police
b) a minority of lunatics who will use this idea to patrol the streets with an attachment to superhero comics and a hard-on for independent law enforcement
The two combined might not be a great combination. I can understand the police not wanting to investigate every video from someone who has spent 16 hours a day at the side of the road looking for anybody who doesn't have both hands on the steering wheel.
However, if the police are using this advice to dismiss out of hand the evidence of cyclists who are not seeking out / aggravating incidents in order to get a thrill from reporting, but riding along minding their own business and have been endangered by shoddy driving, I don't see why private prosecutions wouldn't be the way forward.