As Phil, Stu, and Alan leave Caesars and head towards the limo after forming a plan, a bachelorette party walks across the background and up some stairs. In the next shot they are climbing the stairs again.
The Wolfpack unknowingly help Chow steal $21,000,000 worth of gold. At current market prices, that is equivalent to approximately 1,100 pounds of gold (499 kg). It would be impossible for Chow to carry all of it in a few bags to the car by himself.
During the exchange toward the end, Phil asks Alan to get the last bag of gold out of the limo. As Alan walks toward the limo, the brake lights are on despite the fact that everyone is outside the limo.