So basically no punishment.
https://www.bbc.co.uk/news/uk-england-leeds-62729737
https://policeprofessional.com/news/pc-to-stand-trial-over-m...
But being sacked as a police officer in the UK is a fairly big deal. There's no Fraternal Order of Police to ease you into a cushy security job, and there's no macho culture of celebrating corrupt police. Being charged for misusing one's position would be pretty devastating. Policing in the UK is "by consent" and people don't take too kindly to stuff like this.
Whilst the UK is not a «surveillance state» in the authoritarian sense, and they were certainly not the ones who invented CCTV, we must credit the British for pioneering the concept of ubiquitous CCTV as a tool of urban surveillance, which was complemented by a long-standing tradition of overzealous law enforcement – a legacy with undeniably robust historical roots. It is irrefutable that the UK was an early adopter of CCTV for security and policing purposes[0], much to the bemusement of the guests of Her Late Majesty and His Majesty now.
The British have certainly been instrumental – if not bestowing or spreading it (which is partially true, at least in the case of Australia and New Zealand), then at least influencing – in the widespread adoption of CCTV as a tool for urban surveillance in a large number of Western countries.
[0] One of the first significant deployments in Britain occurred in 1960, when temporary CCTV cameras were used to monitor the crowds at Trafalgar Square during a visit by the Thai royal family – https://www.farsight.co.uk/about-us/history/
Not sure I will take at face value the idea that the Thai royal family were shocked and surprised at overpolicing of potential protestors and that the Thai embassy advance teams had nothing to do with that.
Call me cynical.