Revealing mistake: When people disappear because of the time paradox, the background changes. This is especially noticeable when Johnson disappears, watch the lights on the panel behind her go out. (00:13:35)
Revealing mistake: When the team are heading back to base and we see the skyline for the first time, it's obviously a painting projected onto a blue screen. You can see the line where the set and the screen meet. There is also a white line running across the bottom of the screen. (00:24:50)