OP, I think you need to get back to the driver and examine their account in light of ECP's evidence which seems pretty damning on the face of it. Although the pictures are cropped, they'll have better and so unless the driver claims that the car was out of their control for the period in question how would you hope to convince a POPLA assessor or court that the car didn't enter and leave at the stated times* given that the PCN looks to be PoFA-compliant?
Yes, there is a slim outside chance that ECP don't have landowner authority etc. etc, so the question would be whether after 13 Dec, which is the earliest date on which their legal right to hold the keeper liable kicks in, you want to dispute the issue.
*- I've put it this way because this is the crux of their claim, their assertion that the car was on site continuously between these times is a deduction, not an independent fact.