If you went through an amber light rather than a red one, that isn't an offence.

According to the Highway Code:-

"AMBER means "stop" at the stop line. You may go on only if the AMBER appears after you have crossed the stop line or are so close to it that to pull up might cause an accident."

The amber phase is limited to a maximum of 2.9 seconds, insufficient time to stop from 70mph - and may be a lower time.

Approaching traffic lights on green, it's reasonable to expect them to change so it's considered reasonable to be prepared/able to stop.

Edited by RT on 13/12/2015 at 08:43

AIUI tl cameras are set to operate in respect of vehicles which cross the line after the light has gone red. As with speed cameras there's a tolerance margin so that in pratice there's a second or so of grace - but don't rely on it!!

I didn't see the flash of the one that caught me in Leicester although I'd previously been aware of it catching others.