When Bruce Lee is preparing to fight the martial artist chosen to stop him from teaching the "Guai Lo", their warmup is obviously derived from The Way of the Dragon (1972): Lee is exercising his flexibility, while his opponent, like Chuck Norris, is instead practicing a series of "rehearsed routines."
Rob Cohen:
after Bruce Lee finally defeats the demon, and is back on the set of Enter the Dragon (1973), the director says, "Lost you for a minute, there."
During the ice house fight scene while filming "The Big Boss", after Bruce punches the ice blocks, he and Luke Sun grapple and Bruce gets thrown by Luke into some boxes - during this, the support wire is visible on Bruce's back.
Yip Man: Kung fu is more than a system of fighting. It's a system of thought. You must outthink your opponent, whatever form he takes... because some of them will be more than just men.
Principal Elder: [Bruce Lee drops the message the Elders sent him, interrupting their game]
Bruce, I know that you like to be called Bruce. You have been charged with violating the martial arts code. We've had several complaints from Wu Zuolin and Wong Jack Man and many others. You've been teaching the gwai lo, this must stop.
What are the differences between the European DVD and the uncut version?
A
The reason for the cuts is the European version, because those sequences were shortened in the UK version of the film. Removing those dangerous scenes was apparently supposed to avoid that children imitate them... A detailed comparison between both versions can be found here.