Revealing mistake: When the kids step out of the water and walk towards the house, the floor is already soaking wet from previous takes.
Revealing mistake: When Leslie is fighting the soldiers, one soldier hits a second soldier with his rifle. The rifle can be seen to bend around the soldier's body and then straighten again. (02:12:10)
Revealing mistake: When Charlie Brown stops to watch Snoopy sitting atop the doghouse, eating dog bones, the pile of bones never goes down even though Snoopy takes from the pile three times. (00:03:25)