Depends on the CM and the circumstance. I wouldn't bet on it as there shouldn't be an excuse to miss your large window.
I only went past my window once (about 5 minutes late) to Splash Mountain because of all the traffic after the Soundsational Parade. Nice CM looked at our passes, then her watch, and didn't say anything.
This has been discussed many times around here and while I do not want to get involved in another long debate on the topic but I will say...
At DLR a one hour window is not a large window. When you add in countless possible delays it can be hard to make it within that window. This includes
- Being on another ride that has a posted wait time that turns out to be wrong (happened to me last month when Nemo Subs took 10 minutes longer to board than the posted time)
- Being on a ride that breaks down. (happened to me in May at Epcot when we got stuck on Test Track for 20 minutes and then they offered us a re-ride which took another 5)
- Having it take longer than expected to be seated for dining.
- Younger children in your group which in and of itself has an infinite number of possible delays some of which include bathroom issues.
- Being delayed by things like parades, Fantasmic, and fireworks.
- Parkhopping and an abnormally long line at the turnstiles.
- Weather.
I think strict FP windo enforcement would work much better if any of the following was available:
- windows of 2 hours length
- you choose your own window rather than being offered one window whcih you can't really know until you walk to the ride
- Having one or more central distribution points for all FPs - this would allow you to see all FP options at once and choose accordingly, rather than having to walk around from ride to ride to see what FP windows are available
