Im going to skip the dribble and lay it out.
I rang the RTA in a similar circumstance. If not on the website the camera is not in effect. It cannot issue a fine (in theory, and according to RTA)
No flash = Infrared flash I.E invis to naked eye.
Just post a letter and copy of the fine to the address on the back to alert them to the fact, you may also want to let them know signs had not been on display before the camera. Legally required 3 in total.
Now just a tip if you are chasing a light, you most likely are still speeding through the zone at its normal speed limit.
Hope it helps