Stupidity: As Powell was standing at the completely wrong "eye" in the temple to begin with, all Lara had to do was say nothing of his mistake, he'd never had got the first piece of the triangle to begin with, world safe for another 5000 years.
Stupidity: Jimmy and his friends aren't allowed by their parents to go to the opening of Retroland because it is a school night. What kind of amusement has its grand opening on a school night? It would make more sense commercially to open on a Friday or Saturday night.