Yellow lines don't have to be in perfect condition, and those are in better condition than a lot we see on here. An adjudicator would determine they convey the restriction clearly enough.
You should win on the loading exemption, but you must describe what was involved in the loading that allowed a CEO to turn up, produce a PCN, stick it onto your van windscreen and walk on without you ever seeing him.
They may come back with some tosh, like "loading must be attended at all time"; it doesn't. Post up their response when you get it.