I was taught to always look, never assume that crossing runway/taxiway is clear.
I am always amazed, in the pedestrian world, to watch people waiting for the green light at the crossing and then step of the safety of the pavement into the danger area, where sharks lie in wait for the unwary, without looking. The green says you are cleared to cross, but is it safe? Surely they know of red-light jumpers. It sounds so easy to say, but observation of the real world suggests some guys just don't do it.