It doesn't, but no one is really saying it does. What if the driver posted the reverse vid, showing some guy on a bike doing what he did, plastered the vid with insulting comments and splashing the reg plate on social media etc without allowing any sort of defence?
It is, as someone else already stated, curtain twitching. Do these people upload vids of themselves breaking the traffic laws, splash their own reg plates and cowardly comments on etc? Why not?
Oh thats right, because in their holier than thou crusade they don't deem their own actions as a problem. These discussions typically spiral out of meaning because the posters seem to want a pat on the back and any criticism of the practice of what they are doing is taken as a direct personal attack with no actual discussion taking place. No matter how many times people try to clarify that they don't mean the poster in question - just using the provided material as a point to look at.