Factual error: When Hulk throws Abomination over the post office, the United States flag has only ten stripes, five red and five white. The U.S. flag has 13 stripes, seven red and six white. (00:04:50)
Continuity mistake: When Bruce Banner is attacked by Abomination, he is wearing gym shorts that go roughly midway down his thighs. After he has transformed into the Hulk, the now tattered shorts go all the way down to his knees. Hulk is much larger than Banner, so if anything the shorts should look more like a tattered speedo on the Hulk. (00:00:34 - 00:05:38)
Continuity mistake: When She-Hulk slams the trash can over Gargoyle, he is by the driver-side door near the hood of the car, and the can is taller than the door. When the shot changes, he is suddenly by the opposite end of the door, near the rear wheel, and the can is drastically shorter. When She-Hulk drives away, he is suddenly further away from the car. (00:04:13)
Continuity mistake: When She-Hulk drops Gargoyle to the ground, he ends up next to her right leg, with his head near her knee. When the shot changes to Gargoyle getting back on his feet, her leg is nowhere to be seen. (00:03:50)
Continuity mistake: When Gargoyle is driving She-Hulk's car, one shot shows the top of his head to barely be taller than the steering wheel. When the shot changes, his head is as suddenly high as the rear view mirror. (00:03:21)
Audio problem: When Bruce Banner is saying "Why, did you have another weak spell?" his mouth movement is slightly out of sync with the dialogue.
Continuity mistake: When She-Hulk is reading the invitation to her high school reunion, she is holding the letter with both hands. When Bruce Banner walks into the lobby and asks her if his package has come in, she is suddenly holding the package he is asking about and is no longer holding the invitation. (00:00:25)
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.