Re: Was concerned about the film
With some big films, "re-shoots" or "pick-ups" are actually scheduled as a normal part of production.
No matter the script, often when they are cutting the film together they find things that aren't working or things that need something extra, or think a new scene or alternate scene would work better. Lesser films just work with what they have. Some of the better planned ones schedule in time to do these "pick-ups" a few months after principle photography has wrapped.
This was common practice on The Lord of the Rings films, for example.
Of course, the problems during the production of World War Z was a different type of thing.