Cycling and Risk Taking survey

In Idaho, the law is that cyclists should treat "Stop" signs as "Give Way" signs and red lights as "Stop" signs, allowing them to proceed if the road is clear.

Makes a lot of sense to me as it moves cyclists out of the way of left (or in Idaho, right) turning lorries.

Great if you get to the junction before the lorry, but what if the lights change while you are over- or under-taking a lorry to take advantage of this law?