Continuity mistake: The toon patrol car hits the 2 police motorcycles in the middle of the long alleyway, yet after they crash the cops then land in the middle of the street. (00:59:25)
Continuity mistake: In the scene where Valiant gets his check notice he puts it in his left chest pocket, but when he gets in front of the trolley operator to pay he reaches in his left jacket pocket then it quickly shows him holding it showing the trolley operator. (00:08:55 - 00:09:55)
Joe CampbellContinuity 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: When the movie starts and Herman is launched outside the park, the rattle balls on the bars disappear. (00:01:25)
Sacha

Continuity mistake: When Eddie pours out his whisky, the way he holds the bottle changes between shots. (01:06:35)
MortugContinuity mistake: When Judge Doom is about to dunk the squeaky shoe into the Dip, it seems to stick itself in for him, even though it looks rather scared. (00:33:35)
Continuity mistake: When Roger goes to the Acme warehouse, he brings the gold-plated gun that was in Eddie's car after Eddie took it from RK Maroon. This is a real (not-animated) gun, and when Roger is talking to Benny before going into the warehouse, he's holding a real (non-animated) gun. After Roger bursts through the drain, the gold gun he's holding is animated. (01:21:25)
Vader47000Continuity mistake: When we're first introduce to Roger, the table on the left disappears between shots, and the pillow he rests on keeps moving closer to/away from the door randomly. (00:01:00)
Sacha
Continuity mistake: After unveiling the dip machine, Judge Doom explains its functions while waving his cane in the air. But in the following shot his cane is planted firmly on the floor instead. (01:19:15)
ryguy_1983Continuity mistake: When Roger blasts out from beneath the Acme Factory grate, Judge Doom lifts his head twice in successive shots. (01:21:05)
ryguy_1983Continuity mistake: As Donald plays both pianos at once, the white piano's lid alternates from being closed to open between shots. (00:16:40)
ryguy_1983Continuity 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)
ryguy_1983Continuity mistake: When Eddie breaks out the magnifying glass to get a better look at Marvin Acme's will, his left thumb jumps to a different position on the photo between frames. (00:36:20)
ryguy_1983Continuity mistake: Before Eddie grabs Roger to toss him out of the apartment, a blanket hung over the edge of the pull down bed rearranges itself between shots. (00:37:25)
ryguy_1983Continuity mistake: When Eddie starts browsing through his Catalina pictures, a white cup on the desktop changes its location between shots. (00:26:15)
ryguy_1983Continuity mistake: After blowing his top in R.K. Maroon's office, Roger rests his head on the desktop. Watch how a black ledger appears beneath Roger's head by the time R.K. and Eddie walk over to comfort him a few moments later. (00:24:10)
ryguy_1983
Continuity mistake: When Roger starts reading Marvin Acme's will out loud, Jessica takes her left hand and rubs his head, but once the shot changes her hand is nowhere to be seen. (01:35:05)
ryguy_1983Continuity mistake: After Roger interrupts their kiss in the theater, Dolores looks into Eddie's eyes and says he'd better get going. In the next shot, they're suddenly looking away from each other. (01:03:25)
ryguy_1983Continuity mistake: After fooling Lena Hyena with a road divider, Eddie's necktie blows over his left shoulder. But once the angle changes, his tie is suddenly hanging down again like normal. (01:13:30)
ryguy_1983Continuity mistake: When Eddie and Baby Herman are in the hallway discussing the late Marvin Acme's will, Eddie repositions the baby carriage and starts unlocking his apartment door. He then turns around to face Baby Herman, but between shots his body rotates back to its original position. (00:35:20)
ryguy_1983
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.