An arrestable offence?

A strange story on the Press Gazette site today tells of the arrest yesterday of Manchester Evening News Photographer Sean Wilton, who was bizarrely apprehended whilst shooting a scuffle on the steps of Manchester Magistrates' Court.Wilton was cited for disturbing the peace and obstructing a police officer, but was later (unsurprisingly) released without charge. We realise that the police have a difficult job to do and that mistakes are made in the heat of the moment, but surely it's not hard to distinguish between a press photographer doing his job (as he is entitled to do on public property) and someone involved in or exacerbating the situation? More disturbingly, the MEN claims that more of their photographers were threatened with arrest if they didn't delete their photos of the incident. Cooler heads seem to have prevailed, but still, quite an alarming incident.