I think that Peter (the roofer) will agree that this was not the smoothest running job, because of another job they started a day later than planned, and Peter was not there having been offered a cancellation appointment for some minor surgery. Then the roofing supply company informed him that the reserved tiles had been sold to someone else.
But in my opinion it is how someone reacts to a problem that is more important than the problem itself. We were kept up to date at all times and yes, the project over-ran, but it was finished to a very high standard. The site was left clean, and the guys doing the work were polite and turned up on time every day.