At this point, l can't see anything other than to ask them to exercise discretion and see what happens.
She arrived back, no doubt tired, couldn't find a res permit bay (there aren't any near where she parked, they're all so-called 'Business permit B1) so parked where she did because it was vacant, but she knew she'd done it(this is after all a thrice-weekly restriction) possibly even meant to move before restriction came into effect but forgot, or just didn't notice hence it was left for 5 hours while in contravention.
We don't know.
IMO, just draft the best you can and post here.