I offer this for posters' critique:
The relevant facts IMO:
I was not at work on this day, this is my mode of transport.
The BB belong to my 14 year old son, he was with me. He is a minor.
I was parked on a single yellow line;
i believe i was in the 3hr window slot.
Stop overcomplicating matters e.g. second-guessing the CEO's reasons etc.
If the CEO issued a PCN because they suspected that a BB was being used improperly then simple reps along the above lines should succeed.
But OP, I ask again: who is the registered keeper?