I checked the time and date, and went onto Google Maps history to check my journey, and try to fathom what happened. There is only one possibility, and the timing fits perfectly with the ticket (7 minutes after leaving home). I turned left at the Tessebahn Lights while the light was red. Something I hadn't done while the notices were there, but the notices had been removed. So although they gave the illusion of the rule being removed, the notice had been replaced with a camera.
Of course, since the offence, the lights have been updated also, and there is a now filter light allowing turn left.
OK, it's a niggle, but the biggest niggle is the fine is halved if you pay within a certain timescale - notification was received today, the discounted payment period expired a month ago.
Incidentally, I have renewed my tax and insurance whilst this ticket has been outstanding. So that is an urban myth dispelled.
My Google maps history was fantastic for getting to the bottom of an offence that I wasn't aware of committing. It's a fair cop guv.
