Many years ago when driving into Heathrow central area I was going through the tunnel in the outside lane, as I needed to turn right into the central carpark, when a police car came screaming up behind me on blues and twos. Now in the preceeding weeks they had been enthusiastically fining drivers for crossing the double white lines that run through the tunnel so I held my position.
I could see the occupants having a heated discussion, presumably about my driving, but I was not going to risk a fine for crossing the doubles and anyway the nearside lane was clear. The police car then started furiously flashing his lights so I assumed he wanted me to stop, which is what I did. Only then did the "highly trained" drivers behind seem to grasp the reason for my actions and drove around me, which they could easily have done earlier.