I was knocked off by a driver who came out of a side road through a giveaway several years ago. No serious injuries, only two broken fingers, despite rolling over the bonnet of his car. I was lucky that a following car driver stopped, waited and insisted on giving a statement to the police. I got a payout, after a fight, with a solicitor appointed by British Cycling. The police were hopeless.
I bought a Garmin Virb and wear it on my helmet while commuting in town. I do much more leisure riding than commuting and don’t use a camera then.
It helps, whether you have a camera or not, to let things go. Often after an annoying incident I’ll have my tea and forget about it until the sd card is getting full and it is deleted without even viewing it. Sometimes I view it and decide the incident wasn’t as bad as I thought it was. Sometimes I see ways I could have improved my own safety - it helps not to think about right and wrong but about reducing risk.
Very very occasionally I’ve uploaded something to YouTube. Once I had a very positive response from a glazing company who ‘spoke’ to their driver.
Better than that though I’m convinced it modifies some driver’s behaviour. Fairly regularly a driver will push hard and then back off when they see the camera.
So it hasn’t done what I thought it would do when I bought it, but for me it has been positive, as long as you can be judicious in its use.