The Hulk slips on some hydraulic fluid from a ruptured cable and falls out of the airplane hatch. When he pulls himself up, the hydraulic fluid is gone. A subsequent shot shows the cable still spewing the fluid.
When the Hulk jumps from the 747 plane and runs through a chain-link fence at the end, one can see that stuntman Manny Perry is playing the Hulk, and not Lou Ferrigno.
The fluid spewing from the ruptured pipe in the cargo hold is red, all Boeing Commercial aircraft along with most civilian passenger aircraft utilize Skydrol, a fire resistant hydraulic fluid that is purple in color.
When the Hulk is walking through the plane aisle and is touching the edge of the seats, one can see green makeup smudges on the seats before he touches them. This reveals that this was filmed before and gone back and shot again.
When the Hulk jumps down from the plane, the airbag that the stuntman lands on can be seen briefly at the very bottom of the screen.
At 9:51 the flight attendant places what appears to be sleeping pills in coffee. Plastic medicine pills do not dissolve in coffee, they need stomach acid to dissolve.. It would be impossible for the crew to swallow them without noticing them in the coffee and fall asleep.