Audio problem: In the scene where Valiant is outside and looks over to see the brooms cleaning, notice the bird on the bike coming towards the camera. You hear a bell ringing as he goes by but there is no bell on the bike. (00:09:10)
Continuity mistake: In the scene after Valiant gets rejected by the trolley operator, notice as the trolley operator is closing the door, Valiant starts to fold the check. But in the next shot, he starts folding it again the same way. (00:09:35)
Factual error: Look carefully at the electric trolleys trundling around the streets (and that Valiant hitches a ride on). You'll see that although they have boom arms on top, which are usually hoisted up and connected to overhead powerlines, there are no overhead wires anywhere for them to be getting electricity from. [Notice in the scene when Valiant gives Dolores the check, a Red Car Trolly passes outside the window and sparks fly from the overhead wire contacts. In all of the scenes outside the bar the wires are gone]. (00:10:10)
Continuity mistake: When Eddie hitches a ride on the back of the Streetcar, only its rear power-arm is attached to the overhead cable. Later when Eddie jumps off and says "Thanks for the cigarettes", it has both of its power-arms raised. (00:10:10)
Revealing mistake: The streetcar railway tracks are simply metal strips laid in the road. When Eddie jumps off the back of the streetcar's bumper, you can see that the rails are not in full contact with the road, as there are visible gaps between the rails and the road surface. What's more, the rails do not have the grooves that would be necessary for the cars' wheel flanges. (00:10:10)
Audio problem: The first thing we can hear as Eddie walks upstairs into the bar is a rack of pool balls being broken. But two seconds later he greets his buddy Harry, and at this point we can see how all of the balls have settled and a player is lined up and prepared to take his shot at the corner pocket. It takes more than two seconds for a rack of pool balls to settle. (00:11:20)
Continuity mistake: When Eddie first walks into the bar, he approaches Earl - keeled over on a table. Earl is wearing his hat, but one shot later the hat is lying flat on its top so that Eddie can place it back on his head. (00:11:20)
Continuity mistake: After Eddie questions what happened with Earl, his friend with a notepad writes "Laid off." But he grips the pad in a different manner between shots. Note the position of his index finger when he shows Eddie the message. (00:11:35)
Audio problem: When one of the bar patrons talks about Earl's two week notice, he says "Put the poor guy on two weeks' notice," but at the point where he says "guy" his lips are forming an altogether different word. (00:11:40)
Continuity mistake: When Eddie hears his friend has been laid-off, Delores puts her hand over the glass to remind him he needs to have the money by Friday and she takes her hand off the glass when the camera pans up to her face. When it cuts back to Eddie her hand is still over the glass. (00:12:00)
Continuity mistake: In the scene where Valiant is in the bar and just learned that his friend has been laid-off he takes a drink but Dolores puts her hand over it. In the next shot she has a shot glass in her hand and a bottle, but when Valiant shows her the check, both the glass and the bottle are gone. (00:12:00)
Continuity mistake: When Eddie gets the camera from Dolores, the way he holds the camera changes in the next shot. (00:12:15)
Continuity mistake: When Angelo is messing with Eddie you see Angelo holding an egg. When Eddie grabs him you can see the egg is suddenly peeled. (00:12:55 - 00:13:05)
Continuity mistake: After Eddie kicks out the stool and forces a hard-boiled egg into Angelo's mouth, the eggshell fragments on the bar rearrange themselves into a neat pile. Also, two more eggs appear on the bar, which can be seen after Angelo gets on his feet and turns around. (00:13:40)
Revealing mistake: As soon as Eddie walks into the Ink & Paint Club to see Donald and Daffy on stage, a shadow of one penguin's drink tray is cast on the wall near stage left. However, the penguin's shadow isn't animated into this shot. Instead what we can see is a shadow of the pole, which was used by puppeteers to carry the tray around the club before any animation took place. (00:15:00)
Revealing mistake: When Daffy gets thrown into Donald's grand piano, a wire is visible on the upper left side of the screen - closing the lid on his beak. (00:15:40)
Continuity mistake: When Mr. Acme meets Eddie at the joint, he squirts the magic ink at him. The position of the things on his table keeps changing between shots. (00:15:45)
Continuity mistake: As Donald plays both pianos at once, the white piano's lid alternates from being closed to open between shots. (00:16:40)
Continuity mistake: During Donald and Daffy's piano duel at the Ink & Paint Club, the grand piano's lid opens and closes on its own while Donald is performing simultaneously with his hands and tail. (00:16:40)
Revealing mistake: During the piano duel finale, Donald blasts a cannon at Daffy and the grand piano collapses - seemingly from the impact. But if you look closely there are actually ropes pulling the piano's legs from somewhere offstage. (00:17:05)
Answer: There's really a lot of possible reasons he hates other toons. There's a whole Roger Rabbit book and comic book series that explain Doom's background more. In the film, he's greedy and wants to destroy Toon Town to build the freeway to make more money. In human disguise he's also seen as merciless and is just punishing toons to maintain law and order, etc. Although that's just an excuse to kill toons as well. However, not explained in the film; as a toon he was cast as the antagonist in cartoon films until an accident one day left him thinking he was an actual villain (as opposed to just an actor playing one). That's when he began his life of crime, including killing Teddy Valiant. So his hatred of toons is more about him being evil and not a personal vendetta against them, like Blade's motives.