Goofs

Mr. Han moves his left hand before it is revealed to be fake.

Han describes his prisoners as "Old men who don't care where they sleep." Dozens of emaciated old men, who are presumably not fed or treated well, are crammed into a cell. After they are released, they turn into dozens of healthy young men, physically fit and ready for a fight.

When Lee breaks into Han's underground lab for the last time, he is wearing black socks. The next morning, when he fights Han (after being locked up all night and never changing clothes), he is wearing white socks.

When Han walks Roper through his museum, the various hands are all (correctly) left, until they reach the skeletal hand that was Han's real hand. It's a right hand.

Mr. Han places the cat on the guillotine facing the rear (away from him and Roper). When Roper rescues the cat, it is facing the front (towards him and Mr. Han).

In Lee's final fight against Han, Han is wearing a false hand with four blades. A number of injuries inflicted only leave three slash marks. However, the blades are not all the same length. It is perfectly possible for only two or three to leave a wound.

The wire attached to Mei Ling's dart is visible before she blows it up in the air.

When Lee investigates the grounds, he has to jump into a tree to avoid being spotted. The jump was obviously filmed in reverse.

When Mr. Han takes Roper to his secret underground lair, the guillotine "elevator" starts to descend just before Han pulls the cord to trigger it.

When Roper is being ferried to Han's junk, he has a ludicrous number of suitcases with him on the skiff. The skiff is sitting impossibly high in the water considering there is the oarsman, a 200 pound Roper, and about 20 suitcases on board. The suitcases must be empty.

During the first infiltration of Han's underground lab, Lee slips under a metal railing to climb back up the rope. When he goes under the bars, they bend and return, revealing that they are made of rubber.

During the second infiltration of Han's underground lab, Lee is hiding out of shot whilst a nurse walks away from the camera through a doorway. When the nurse exits from the shot, Lee's shadow immediately appears on the floor from the left, revealing that the sequence was not filmed continuously.

In the final fight in the courtyard, Bruce Lee can be seen running around frantically on the right side of the screen, choreographing the fight.

When the one guard attacks Lee underground with the nunchucks, the shadow of a studio light appears on the crates in the background.

When Lee and Han are fighting in the trophy room, Lee delivers a right crescent kick to Han's face. As Lee quickly moves off to his right, a microphone or lighting bracket is visible to the left.

At the beginning of the movie, Lee rebukes his student for looking down when he bows during a lesson, saying "never take your eyes off your opponent." Later in the movie, Lee does just that during his fight with Oharra. He looks at Han long enough for Oharra to grab Lee's ankles, in an attempt to cheat.