Cougar,
Whilst it is Possible That the NIP has been served late even then the s172 requirement must still be met – ie he must meet his obligations to identify the driver (or explain why he can’t – eg “at the time and date stated the vehicle was at XYZ and the only set of keys was in my pocket at ABC, I have receipts which show I was at ABC at around that time. No other person has access to, or had permission to drive the vehicle at that time”)
Most often when people think the “14 day rule” gives them a get out clause it turns out that the NIP they received was not the first one issued but, there is a lease company, company car, previous keeper, incorrect address etc which got the original properly served notice on time.
Beware of internet advice to ignore these things. There is no obligation for them to provide evidence prior to court, but most camera departments will provide photos to help ID the driver (some do it online). If there is a belief you may have been cloned you may be asked to provide photos of your vehicle (or they may send traffic officers to compare it to their pics).