Will try to be as brief as possible, apologies for any irrelevant info and detail.
Stopped on pavement to unload (a couple of bags and also dropping off a passenger) last Saturday evening 7th March and was very surprised to find a CEO doing his thing on his handheld when I returned to the car. I engaged in conversation and said I was (i.e. had been) unloading (I probably sounded rather surprised). His manner was reasonably helpful, he said it was too late, he had already done whatever, I said something to the effect that the car had only been there a very short time (I was still startled to find a CEO there in such a short time at around 9:45pm on a Saturday evening). He said he had been observing the vehicle for a long time which didn't make sense but I didn't question this further. He took some photos and a minute or two after I had come out to the car he handed me the PCN.
I continued the conversation, he said that a neighbour had phoned the Council to report the car, CEOs don't just hang around the streets on a Sat eve. On reflection I feel it more likely that it was a pedestrian who made the report, there was one in the vicinity who I think walked past as I was unloading. The CEO was trying to wind down the conversation and after a couple more amicable exchanges about parking and loading regulations he departed.
It's hard to estimate how long I had left the car unattended without re-enacting the circumstances and using a timer. I would think a few minutes max.
There is no driveway that can be used here. I am aware that it might be argued I could have legally parked in the road (and even left the car there overnight) on the single yellow line (there's a waiting restriction 7am-7pm Mon-Sat and a loading restriction 7-10am and 4-7pm Mon-Sat). However it's a busy major road (A298, albeit generally quiet late on a Saturday evening) with heavy traffic (a lot of HGVs plus fire engines police cars and particularly ambulances). There is also a slight double bend and sight lines into the distance are poor the other side of the road because of a very narrow pavement and fences on property boundaries. The location is just before a staggered junction (it is about 10m or just over to the start of the curved kerbstones). Stopping in the road would cause vehicles the same side to have to cross over the central line marking (actually a central hatched area begins here), I'm not sure if there is enough road width even for 2 smallish cars to pass each other comfortably next to a parked car here let alone larger vehicles. I always stop on the pavement at this spot where it is wide enough to leave plenty of room for e.g. wheelchairs, instead of stopping in the road, when loading/unloading.
PCN states vehicle observed at 21:42 and time of contravention 21:45 (so allowing for the truncation of the seconds that's a period of between just over 2 minutes and just under 4 minutes). Would the “time of contravention” be the time the CEO started entering the vehicle's details or the time he printed out the PCN? From the picture evidence on the Council website, the first picture was taken 21:42, before I had come out to the car. The 2nd (from bodyworn camera?) suggests that someone (!) got as far as making to open the driver's door (21:44 but possibly the timestamp not absolutely synchronised to the other camera) without noticing the CEO who was standing behind the car and took image 3 (21:45 timestamp) after I had initiated conversation. So it looks to me as if some of the observation period 21:42 to 21:45 was after I had come out to the car.
Merton on their website state
“We are only required to observe your vehicle for 2 minutes”
I was probably unlucky and the CEO must have been just round the corner when whoever it was phoned the Council. I've not previously found a CEO in attendance with such a short period of the vehicle being unattended (that's over many years) like this (I am usually pretty diligent about not leaving the vehicle for more than a moment though have once or twice forgotten to move it promptly but not on this occasion).
Where (apart from you amazing advisors here) is the best info on loading/unloading regulations? Highway code says... Rule 247 “loading … may be permitted where parking is otherwise restricted”. Rule 244 “You MUST NOT park partially or wholly on the pavement in London or Scotland. Exceptions are allowed in limited circumstances” Rule 243 “DO NOT stop or park: … opposite or within 10 metres (32 feet) of a junction … on a bend”. Rule 242 “You MUST NOT leave your vehicle or trailer in a dangerous position or where it causes any unnecessary obstruction of the road.” I consider Rule 242 my main defence as I judge parking in the road here to be an unsafe location to leave the vehicle for all the reasons I have mentioned. The Civil Enforcement Handbook has, for code 62, “Loading/unloading allowed: Yes, but only if it is essential so as not to cause an obstruction and cannot be carried out elsewhere.”
Thanks for any assistance. I'd like to contest this and would appreciate advice on how best to make my case. And also to make sure that I correctly understand what is/is not permitted and hence how best to load/unload in the future.

