Meh, there is a pedestrian crossing near me that is broken, literally if the person presses the button next thing you know the traffic light is red with no care for the amount of traffic going through the lights or anything. This is why I can understand the OPs story, because the exact same thing happened to me. Now I know it is there you prepare for it, but you don't expect a pedestrian to walk up to a crossing as you are right on top of it and the lights to change straight to red with a large queue of traffic behind you! Safer option in this case is to go through the red than emergency stop and cause a pile up.
As well as doing the generic safe driving that an ADI teaches you, you also have to be flexible and react to individual situations. To lecture on limited information is unwise.