Not sure if you actually read the rules. What I saw in the video does not require a permit and nothing illegal was done.
You do not need a permit to fly a private drone, within certain locations. Flying over structures (and a public highway) is not allowed. It could be allowed if you have a commercial permit. If you have a commercial permit, you will definitely know the rules.
Flying over a public highway may well get you into trouble with the CAA - there are lots of other circumstances where 'model' flying can get you into trouble, which is why there's a training programme for RC (radio control) model pilots administered by the British Model Flying Association. That programme produces (generally) responsible model flyers who are unlikely to fall foul of the regulations.
Drone flyers, who may well know nothing of the CAA ANO, or the BMFA training schemes, may well end up in hot water if they try to film cyclists on a public highway. There have already been legal cases relating to drone flyers breaching the ANO.
Which is exactly what Drago and Classic33 are saying.
As a long-time model flyer, and member of the BMFA, I'm simply advising anyone who might think of flying a drone over a public highway to film a cyclist - be aware of the potential consequences.
FWIW, I waiting for a neighbour to pop round to bring me a drone found on his son's farm near Wrexham. Someone's lost one and they won't be getting it back. It'll be going in the bin. Crushed. These things may well be the end of responsible RC model flying in the UK as we know it, and it's been for decades - it's already a big problem in the USA. We are waiting for someone to fly a drone into a light aircraft and create an incident. Just watch this space....
In this respect, Drago is spot on.