Trivia: The prison guard is played by Mark McClure, who played Jimmy Olsen in the Christopher Reeve Superman movies.
Continuity mistake: While Bruce is on the cliff before speaking with Arthur he has his hood on, but in the immediate next shot the hood is off. (00:11:20)
Continuity mistake: When Flash calls himself "a snackhole", he holds the pizza carton with the hand at its corner, then more towards the middle. (00:38:45)
Continuity mistake: When Clark and Bruce are watching people move, a man can be seen picking up a box next to another standing by a workbench. In the next shot, the man with the box has completely vanished.
Continuity mistake: After the villain's hair is drenched in water, Batman dangles him over the ledge - yet in the next shot, his hair appears perfectly dry and neatly brushed. (00:03:14)
Continuity mistake: When Wonder Woman stands on the Justice statue, she first grips the upper-middle of the sword. In the next shot, her hand is holding the upper part instead.
Answer: "Surely they'd figure it out" is hardly a suitable solution. If they knew how to destroy them, they would have. They did the next best thing by hiding them in different places.