Continuity mistake: After the Hulk breaks the wall to escape at the end of his second transformation, he is wearing black pants instead of his usual beige pants.
Revealing mistake: When the Hulk is lifting his left foot at the beginning of his first transformation to break free from the "leg shackle", there is a close shot where we should see his toes. But we cannot see them because he is wearing some green pantyhose with brown soles to protect his feet.
Chosen answer: Bruce has always been the character's middle name. In the comics he is Robert Bruce Banner, here he is David Bruce Banner. Apparently the executives behind the show preferred the name David.