Continuity mistake: When Bruce Banner is in the soup kitchen, there are several paneled windows behind him. When he is shown standing up from his seat, it is only a brick wall behind him.
Continuity mistake: When Ghost Rider crashes his motorcycle out of the building with Talbot in tow, he is holding Talbot around his midsection. When the shot changes to them in free fall, he is gripping Talbot by his collar. When they land on the street, he is back to holding him around his midsection.
Continuity mistake: When the helicopter is put in hover position for Talbot to shoot Hulk with the tranquilizer weapon, you can see that the pilot seat is unoccupied. When the shot changes, Talbot is suddenly in the seat.
Continuity mistake: When Ghost Rider tracks down the Hulk at the salvage yard, he pulls his motorcycle right up to within a couple feet of the fence. When Rick Jones pulls up perpendicular to Ghost Rider, one shot over Ghost Rider's shoulder shows pavement behind Rick instead of a fence. A couple of shots later, the fence is directly behind Rick. Another couple of shots later, Ghost Rider is shown from the back saying "An innocent victim shall suffer" and he is suddenly facing a group of buildings instead of the salvage yard. All remaining shots in the scene place Rick and Ghost Rider back by the fence.
Continuity mistake: When Bruce Banner is in the soup kitchen, he is seated in a chair next to the one at the end of the table. In the shot just before the explosion, he is getting out of his chair, which is now the one at the very end of the table.
Continuity mistake: When the Hulk lands in the streets of Chicago after his battle with Ghost Rider, he is in the middle of the street. When the shot changes, he is suddenly next to the curb and a mailbox.
Continuity mistake: When Talbot arrives to attack Hulk, he is wearing a hat. When he falls out of the helicopter, the hat is missing. When he lands on the roof, the hat is back on his head.
Continuity mistake: When Doc Samson throws Hulk through the train station, it is a wooden building. When Hulk crashes out of the back side, it is now a brick building.
Continuity mistake: When Hulk jumps up onto Talbot's helicopter, it changes color from an army green to blue.
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.