Continuity mistake: When Jennifer Walters is first introduced, her fingernails are unpolished. Later when she is restrained in Dr. Doom's lair, her fingernails alternate between being painted pink and red. Given that she and Bruce were running for their lives, she wouldn't have had time to paint her nails. Later when she transforms into She-Hulk, her fingernails turn green with the rest of her body, but if her fingernails were painted, they should still appear that color, as her skin and hair turning green wouldn't magically remove nail polish.
Plot hole: After Dr. Doom's robots abduct Jennifer and load her into the aircraft, Hulk hitches a ride all the way to Doom's estate, falling off the aircraft and breaking into the estate before the aircraft has time to land. Despite this, Dr. Doom already has Jennifer secured to an infirmary table and medical machinery by the time Hulk confronts Doom.
Continuity mistake: When Bruce and She-Hulk are hitchhiking, the sign for New York behind them changes size and lettering. When it is first shown, it is significantly taller than both of them with the lettering reading "NeW York" (sic) in a thin and long font type. When the shot changes, the sign is much shorter and the lettering now reads as "NEW York" in a more block-lettering style.
Factual error: The opening shot of this episode incorrectly depicts the Lincoln Memorial Reflecting Pool to be located between the Washington Monument and the U.S. Capitol building. In reality, the reflecting pool is located between the Lincoln Memorial and the World War II Memorial, with the Washington Monument roughly 1/5 of a mile east of the World War II Memorial, and the U.S. Capitol nearly a mile and a half east of the Washington Monument.
Other mistake: This show is in the same continuity as the Fantastic Four series from around the same time. However, in Fantastic Four, Dr. Doom has a German accent, and in this episode, he has a slight British accent.
Factual error: When Hulk throws the Humvee at the helicopter, the pilot bails just before it explodes and manages to deploy his parachute. The helicopter was hovering roughly 30 feet above some buildings. That's not nearly enough distance for the pilot to have deployed his parachute before he fell onto the roof of one of the buildings.
Answer: The Hulk is a giant brute who smashes everything in his path when he is angry. In Ang Lee's "Hulk," General Ross, played by Sam Elliot, explains it to his daughter.