Hehehe the exact location is probably the roundabout off the Doha Expy at Gharafa immigration. I hate the traffic light there, because the timing changes all the time. Worst thing is the period, when amber flash for some time and then it goes to red suddenly. Worry not about the police, they are usually busy with their phones playing games.
It happened to me too - it was blinking and I was looking to the left if it's safe to pass and entered the R/O on red sign somehow. There were actually 2 police cars waiting on the roundabout and third police car entered the R/O on red sign with me. I was really scared and was checking MOI website for a week every hour - but no fine.