I have the same camera, and one thing I've noticed is that the on-screen GPS speed differs to the speed on the video file - sometimes there can be 5mph more on the video than recorded via the GPS metaData...so I do agree that the camera car could have been on the limit and not speeding as per the initial video.
See attached - the software shows a different speed as to the video...
He should get them checked by a professional because they definitely are not. I also had this guy behind me and was dazzled by the rear view mirror in broad daylight.
Well this is an easy one, right? Go onto your local Police website, report non-injury traffic incident with car details and presto! 6 points for the idiot.
Please remove all social media commentary and make the video non-public until such a time as any and all associated court proceedings have concluded.