BB,
I agree about police time being used for this sounds a waste, and I'm only able to speculate from my own employers point of view.
I don't know who within GMP would even be able to access bulletin boards and forums in relation to such offences. I know who deals with the summonses generated by the camera vans and the "iffy" cases. Most are time served cops with only a few years service left who generally have spent a lot of time in the traffic world. They wouldn't be out on the streets anyway due to age, injury or just winding down to retirement. But to find him in the vast, Earth encompassing mess that is the world wide web, seems almost too much of a coincidence to bear.
I suspect a tip was passed.
He hasn't been gaoled for the speeding, he has for the criminal offences of perverting the course of justice.
Pete