Around 26m, when Jim was stabbed, it can be seen that the knife wound would be somewhere in the lower right torso. But when Jim falls down, the stab wound is on the upper left part.
After Cinnamon stands in front of the wind machine to make herself look disheveled in the "storm", she bangs on Bert's front door, and he lets her in. A moment later, when she's sitting on the couch, her hair is once again perfectly coiffed.
When Connie takes Jim's "body" to the lumber yard for incineration, Connie enters the yard in a Chrysler Imperial. Connie then gets out of a Lincoln Continental. Finally, he takes Jim's "body" out of the Chrysler.
Barney's 'repair' of the cut telephone cord would have failed. He reconnected each of the four conductors, but did not insulate the individual conductors when taping the splice. This would have caused the telephone line to short out, making the telephone unusable. In addition, because of the short, none of the telephones in the entire house connected to that telephone line would work.
Despite Barney and Willy raising and lowering the window to gain entry into the room, the sleeping gas continued to flow in through the hole in the window.
The team runs wind machines and create fake lightning and thunder for a long period of time and none of the other neighbors notice. Even if the neighbors were not close someone should have noticed the disturbance.