Another thing might be crucial equipment. One of my friends works in the film industry, and they told me the insane dance every that goes on every set. A-lister actors, directors, and insanely expensive equipment is flown in from all around the world, and they literally often have hours of having everything in the same place, during which window they have to record the scenes, then everyone flies off to somewhere else, and the meter is ticking to the tune of god know how many thousands of dollars per hour. No mistakes or delays are possible.

He once told me of a story when some exotic piece of equipment broke, and there was NO replacement on in Europe. After a mad scrable, they did find something and they had to fly in that special camera rig thing on a private jet.