When Charlie and Ben are at the table coloring, Ben's crayon changes from yellow to red and back again between shots.
Just before the puppet show, the Child Services investigator takes a cookie. When Charlie, Marvin and Phil ask for privacy to discuss the missing child Flash, the investigator is holding the cookie. The scene looks at the puppet show and then back to the investigator putting the cookie in his breast pocket. The scene moves back to the puppet show and immediately back to the investigator who now has the cookie back in his hand again.
When they are taking applications at the "lemonade stand", Crispin kicks Charlie's left ankle (at 25:02) but when Charlie reaches down to rub his ankle (at 25:03) he grabs his right.
When Charlie pulls up to the Academy for their appointment, he emerges from a car stopped parallel to the steps. In the next cut, the car is parked diagonally in relation to the steps.
During the puppet show, the girl with the glasses is sitting far from the camera, but in the next shot, she's the closest person to it..
When Charlie and Phil remove what appears to be a beehive, it is actually a hornet nest.
When Phil is singing and playing the guitar, many of the kids already know the words and sing along with him (at 28:29). They must have rehearsed this scene too well.
When the Child Services inspector comes and is offered a cookie, Charlie comes in with the tray and oven gloves on implying that the tray is hot (at 1:03:54). But on several occasions the tray is resting against his chest, like it isn't burning him.
When Phil is standing on the sofa, playing the guitar, the music keeps going when he's not strumming.
At the advertising agency Charlie Hinton quotes the Red 4 dye used in the breakfast cereal as being harmful. Red 4 dye had already been banned by the FDA.
Early on, the kid who is only supposed to speak in "Klingon" is talking to another kid on the steps during the mission statement, and also singing along with the songs.
When Charlie and Ben are coloring in the dining room, Ben draws a picture of the two of them and tells Charlie he gave him a mustache, and Charlie says it's a nice green mustache, but before their conversation, Ben shows Charlie the picture (at 1:00:03) and there's no mustache.
When Charlie is trying to convince Kim that the daycare center is a good idea, he follows her into another room holding Ben's hand. After Ben bangs his head, Charlie says (at 20:12) "You don't want to be rubbing your head like that". He meant to say "banging" but was distracted by the fact that he had to rub Ben's head in the scene.
At 19:42 Charlie tells his wife that he and Phil applied for the child-care license the previous day. He couldn't have, as he and Phil had just come up with the idea in the park earlier that day.