Misuse of powers is a longstanding issue, whether it's the embedded secret policemen who decided that "embedded" meant getting into bed with their "targets".... or the bloke in the 80s who was part of Nukewatch, chasing nuclear weapons convoys on the motorways, who drove a bright orange Cortina with a CB aerial and waved at the convoy drivers. The RAF Regiment who accompanied the convoy (looking like ordinary motorcycle cops) told the local police to arrest him and detain him under the Prevention of Terrorism Act, and they treated him like a potential terrorist. He was released when local CND people rang the police station, asked to speak to Sgt Lorimer, and when they were told they didn't have a Sgt Lorimer, said "Yes you do, he's Special Branch".
(Only matched by Michael Moore's film where he was filming somewhere when he was approached by some people who said they were secret police. Not that secret, then...)
The point is that the police's lying about police being injured, and fishing raids, and dressing up as public servants, all go to reinforce the reason for the protests. It's an attack on peaceful protest.