Plot hole: Hiding in a fridge (or anything else) in order to be conveniently blown out of the way by an exploding nuclear device is absurd beyond belief. The fridge is just so much extra reaction mass and would be vaporised by the expanding nuclear explosion - it wouldn't be daintily picked up and thrown a few kilometers to safety. If it was, why doesn't it land in a shower of similar artifacts which have also been dislodged and thrown around? Incidentally, even if it was thrown out of the way as shown, anyone inside it would be turned into a smear of strawberry jam by the acceleration required to beat the shock and heat wave of a nuclear blast, and then liquefied by the deceleration involved in hitting the ground at that speed.
Continuity mistake: At the start, just as the carful of teenagers joins the convoy of military vehicles on the road, there are very long shadows being cast on the road, which vanish in the following shots. Their long shadows return when the convoy turns onto another road, but disappear again as they arrive at the main gate. (00:00:45)
Indiana Jones: Put your hands down, will ya? You're embarrassing us.
Trivia: In the Mayan temple, Indy comments "I have a bad feeling about this." This line was a running gag in George Lucas' Star Wars saga, and was used by Harrison Ford at least once. (01:46:10)
More questions & answers from Indiana Jones and the Kingdom of the Crystal Skull
Chosen answer: Because the film had a global release date, and premiered the same day in every country in the world. Obviously, the studio felt this was the best day to do it.
Twotall