Close maybe, but tailgateing no. You have obviously never seen a tailgate incident and by that I mean inside 60cm (2 feet) of your rear bumper - that's tailgating. I would suggest there was probably 6 to 8 feet of room. More that legal. By the way clean license for 30 years and over 44 years experience of driving everything from a car to a 40T truck. As for the overtaking well remember its their life they risk give them space and keep out of their way at the end of the day its you need to be safe.
Yeah they made a mistake but it doesn't look that bad. They were driving at a safe speed, indicating throughout. Live and let live, life is too short man..
Doing his job wrong needs to get sacked