Continuity mistake: When Sylvester is testing out the artificial storm cloud he has created, he is holding a dropper with his right hand. But when we see Sylvester in the next shot, the dropper has gone.
Continuity mistake: When Sylvester is on the pogo stick, he grabs hold of Tweety and you can see he has Tweety in his left hand and the pogo stick in the right. But when Sylvester falls into the manhole, he now has Tweety in his right hand and is holding the pogo stick with his left.
Continuity mistake: When Sylvester runs into the yard after throwing the smoke bomb into it, the door of the yard is shut but in the next shot it is open.
Continuity mistake: At the beginning of the short, there is nothing on the front gate door to Tweety's yard. But when Sylvester runs into the yard after throwing a smoke bomb into it, a door handle suddenly appears.
Audio problem: When Sylvester is saying "Down, boy!" when the robot dog is attacking him, his mouth is not moving.
Continuity mistake: When Sylvester is testing the robot dog he has built, you can see there is a piece of paper underneath the radio control unit. In the next shot, the paper has gone.
Continuity mistake: When Sylvester is looking through the window with his binoculars, he looks at Spike and you can see there is a bowl with a bone next to his kennel. But when Sylvester sneaks past Spike's kennel after entering the yard, the bowl has gone.
