The Empire Strikes Back Bloopers 
1. In the scene where the Star Destroyer is blowing up asteroids in search of the falcon, if you watch it in slow motion, you will notice that an asteroid starts to explode before the laser blast hits it. 
2. During the scene where Leia says "Captain, being held by you is hardly enough to get me exited", you can see Harrison Ford mouthing her lines at her. 
3. In the cloud city junk room, during the close-up of 3PO's head, you can see the camera's reflection in it. 
4. Lando and Han switch sides twice during their walk to the "refreshment". 
5. Just before Luke dropss out of the bottom of cloud city, you can see the hand which was just chopped off. 
6. Right before Darth Vader powers up his lightsaber for the first time in cloud city, you can see the uncolored rod. 
7. After Luke knocks Vader off the platform in the Carbon Freezing room, he jumps off too. You can hear him land on a 
trampoline and see his head pop back up for a moment. 
8. In the scene where Darth Vader asks Piett, "Did your men disable the Millennium Falcon's 
hyperdrive?" Piett's rank insignia switches from the left side to the right side of his uniform. 
9. When the Falcon first goes into the astroid field, one of the Ties following it, get's smashed into a asteroid(it's the first one to crash). If you slow it down, you can see the pilot falling out on fire. I swear it is there! It might only be noticable on the 
Widescreen version, but it's there! 
10. When Luke and Vader are duelling on the catwalk above the shaft on Bespin. Vader's onslaught is forcing Luke backwards. Vader takes a very aggressive swing towards Luke and chops through a railing. You will notice however some black tape of 
some sort, most probably a pyrotechnic device of some sort, exactly where Vader slice through, causing a lot of sparking. 
11. Chewie takes cover around a corner on the Cloud City while stormtroopers fire at him. Two shots come at Chewie during this sequence. The first one hits the wall and leaves a black charred hole. A second shot comes seconds after and hits the EXACT same spot on the wall. Talk about accuracy. 
12. Justafter Luke knocks Vader off the deck in the carbon freezing chamber. After Vader falls, Luke walks around a large 
machine and doesn't shut his saber off, you can see him reach back and trade for a hilt with a hidden stagehand. 
13. During the scenes when Han is about to be frozen in Carbonite. Before he is lowered into the freezing chamber, he has 
shackles and straps around the upper part of his arms, which holds them to his body. The shackles are removed by an Ugnaught, but the strap is not. However, in Return of the Jedi, when he is unfrozen, he no longer has the strap on his arms. Also, in the same scenes, for close shots of Han, he is not wearing his vest, just his white shirt. When the camera cuts to long shots, Han is wearing his vest. Also, his shirt is untucked before he is frozen, but tucked in when he is thawed. And finally, upon close inspection, you will notice that he is wearing a double breasted shirt when he is thawed in Jabba's palace, but is wearing a tunic style shirt when he is frozen on Bespin. 
14. On Bespin, after C-3PO has been dismembered and his parts are spread on the conveyor belt. Cloud City, C-3PO's parts are on the conveyor belt. Chewbacca enters the "junk" room to collect the remains of Threepio, and in the close-up scene of Threepio's head on the conveyor belt, you can see a reflection of the camera and several of the crew. 
15. In the Sceen where Han is being frozen in carbonite. He is wearing a single breasted Shirt and straps on his upper arm. 
When Leia takes Han out of the carbonite Han is wearing a double breasted shirt and no straps on his upper arm.