I would not have continued the argument in the way that you did. It comes across as goading and threatening. After the first interaction you should have left it and then prepared the reports you wanted to. By continuing the argument for several minutes along a long stretch of road you were in danger of causing a distraction to other road users, as well as an over-reaction from the driver of this vehicle.
So I was ragging my ecoboom around lakeside gp then look to my left to see an m140 being driven by an ice gem, for one minute I thought I was still off my nut but then looked again, it was just an eager Dougy Martin.
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...
I would not have continued the argument in the way that you did. It comes across as goading and threatening. After the first interaction you should have left it and then prepared the reports you wanted to. By continuing the argument for several minutes along a long stretch of road you were in danger of causing a distraction to other road users, as well as an over-reaction from the driver of this vehicle.