Visible crew/equipment: When Eddie tries throwing Roger out the door, Roger explains that he's being framed by somebody. Here, notice the film crew's power supply cords running along the floor from the hallway into Eddie's apartment. (00:37:45)
Visible crew/equipment: When Roger and Eddie get in a truck and there's no key, Roger hears the voice of Benny the Cab in the back of the truck. He then slides through a little window and his love letter to Jessica pops out of his pocket. A black glove can be seen pushing this letter through the window. (00:55:15)
Visible crew/equipment: When the weasels search for Roger in Eddie's office, there is a shot where Smart Guy kicks a box aside right after he tells the others to stop laughing. To the right is the shadow of a puppeteer pulling the box up in the air. (00:42:45)
Visible crew/equipment: In the alley scene, where the two motorcycle policemen collide with the police car, and the motorcycle cops fly over the car, you can see the landing pads placed on the pavement to cushion their fall. (00:57:05)
Visible crew/equipment: In the scene where the weasels are chasing Roger and Hoskins and the weasel says, " I'm going to blow his head off ", look at their icon on the side of their door then quickly look to the left you can see the bumper and back end of the car that is driving the camera. (00:56:05)
Visible crew/equipment: A crew member's hand is visible turning the steering wheel of Eddie's beat-up Plymouth when Roger skids it to a halt. (01:17:35)
Visible crew/equipment: Set lights are visible on the ceiling for a few shots in the scene where Eddie and Baby Herman are discussing Marvin Acme's will. (00:34:30)
Visible crew/equipment: When Eddie grabs a newspaper from Baby Herman, you can briefly see the mechanical arm used to hold it - sticking out of the carriage for a split second. (00:35:00)
Visible crew/equipment: In one shot where Eddie leaps into a wall of pogo stick boxes at the Acme factory, a springboard used for the stunt is partially visible behind the red banana skin containers. (01:24:35)
Visible crew/equipment: Right before Eddie goes in for a closer look at the will in Marvin Acme's patty cake photo, a boom mic is reflected in the magnifying glass. (00:36:15)
Visible crew/equipment: When Eddie is bouncing up and down on the pogo stick at the Acme Factory, two wires are visible around his left and right shoulders; just before he bounces up into the light fixture.
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.