There is some logic in what you're saying, but the alternative could be that the double-yellow lines are there to stop parking so that people can turn their car round. Earliest GSV view is 2009, and the lines are there then, with the road blocked off.
Can you please post the back of the PCN so we can check the "small print" that may contain a fatal error. PCN content is defined in law.
The Traffic Regulation Order must contain the details of these lines, so you might care to look there on their website if the TROs are available : -
https://www.trafficpenaltytribunal.gov.uk/tro-library/No DYLs in the TRO = no contravention