These things absolutely happen. That's true of any project. However, it does beg the question a bit of where the money is going. While no one here knows true numbers, much like the studio side, the design side of Disney has MASSIVE budgets. That should translate into better design checks, testing, etc. These systems (from a plumbing standpoint) shouldn't be that exceptionally complex. So, I think it's fair to raise some questions about allocation of funds if all these things are happening in a project that has taken (as a whole) so long overall.