We need a bit more info. The first photo on the PCN clearly show he is in the traffic lane with his rear offside wheel in the central hatched area, with brake lights on. The second photo doesn't show his vehicle at all, just an approaching bus. As its a red route, one must not stop, unless the traffic flow stops. Was he stopped waiting to enter the parking bay by the shops ?
The PCN is served under the Traffic Management Act and their only evidence is a video, so he could ring them ask for it. This will stop the enforcement clock for about 14 days whilst "quill pen and ink, and powdered wigs" Transport for London send it by post as a DVD. There is an ongoing row about this, because DVD readers on computers are now rare, and even London Tribunals are getting concerned at such unhelpfulness. Most councils nowadays put their videos on-line with access using PCN Number and car reg.