Anecdotally at least witnesses often side with drivers.
I had a collision recently where I was travelling up the nearside in a cycle lane and got left hooked by a non indicating car. One other motorist stopped to shout at me for going up the inside too fast and another pulled in and asked the
driver if he was OK, she seemed very concerned for his wellbeing after having had a scary cyclist ping dangerously off the side of his huge pickup.
Had I not had the camera I would find myself paying for the damage to both our vehicles because he'd have witnesses willing to state he indicated and that I was riding dangerously, but luckily my camera told a different story, that's the first time I've ever felt like it's 'them and us'.
The tune of 'I was definitely indicating' stopped pretty quick.
I'm not sure I'd call myself lucky after 3 surgeries and potentially facing a 4th, two for a shoulder injury that may well be hard to prove was caused by the accident
Obviously that's a horrible thing to have happen but you'd be in a worse position had you been hit by the scummy type to lie and cheat their way out of the problem.