SNAFU. Only the person named on the Notice to Keeper (NtK) can respond. If the Keeper wants to throw you under the bus, then that is their prerogative and all they had to do was do what it says in the NtK, which is to give ECP the drivers details and pass the NtK to the driver.
However, irrespective of whether the Keeper or the driver ends up being the liable party, I can tell you that if whoever it is follows the advice you receive here, you won't be paying a penny to ECP.
No initial appeal is going to succeed, so stop panicking about that. Neither is there much chance of a POPLA appeal succeeding. The odds are that this will eventually be a county court claim which is easily defended and in due course will be either struck out or discontinued.
I'm sure others will help with a POPLA appeal. I would not waste my time in an ECP case.
If I'm correct, and the POPLA appeal is unsuccessful, do not worry. The POPLA decision is not binding on you and has no consequence moving forwards. All you must do is ignore all debt recovery letters that will cone your way.
Debt collectors are powerless to do anything except to try and persuade the low-hanging fruit on the gullible tree to pay up out of ignorance and fear. Never, ever, enter into communication with a powerless debt collector.
When you receive a Letter of Claim (LoC) from DCB Legal (not DCBL), come back and we can provide a suitable response. Likewise, when the claim form arrives, we will provide a suitable defence and further advice.
I would be happy to accept £100 bets that this will eventually either be struck out or discontinued before they have to pay the £27 trial fee.
Any takers?