Plot hole: Bond would not have had (nor taken himself) time to lay a complete and careful clown make-up while changing clothes in the circus trailer.
Plot hole: When Bond is on the roof of the train, he opens the roof panel on the rail car, jumps down into the car, and puts on a gorilla suit to hide. He does all this while the knife thrower is in the small car. Wouldn't the knife thrower have heard something? The roof panel opening alone would have amplified the train's noises, not to mention the air that would have blown in.
Plot hole: The Fabergé egg General Orlov presents to Kamal Khan, then destroys, is the actual egg - not the "fake". We know this because Bond put the transmitter in the actual egg. (00:58:18 - 00:58:50)
Plot hole: Bond falls off the train, and in the time it takes him to reach the air force base the train has arrived and unloaded all of the equipment including the cannon, staged a town parade including the cannon and erected and filled the big top with an audience. You could argue that the big top was sent ahead but the unloading and use of the cannon couldn't have been done in the time frame - would take at least 4-5 hours.
Plot hole: When Bond wakes up in the monsoon palace, his watch is still beeping with the activated tracking mode. Wouldn't somebody have noticed the constant beeping while he was brought there? The tracker is shown to have a range of several hundred meters, so it would certainly have been in range of the transmitter at least part of the time while Gobinda dragged him back to Kamal's palace.
Chosen answer: The satisfaction of knowing he'll win, the thrill of pulling one over on someone; maybe like Goldfinger, he just doesn't like to lose under any circumstances.
Captain Defenestrator