Other mistake: When Monica realizes that the cookies were the Nestle Toll House recipe, Monica tosses the yellow bag of Nestle brand chocolate chips to Phoebe, and the brand name has been partially covered so it looks like "I Iest" and the Toll House logo on the side has also been partially covered.
Other mistake: Right at the very end, when Joey is in the fat-suit and picks up a piece of food and says "How you doin'?" he doesn't put it in his mouth, he just lifts it to his lips, stops, and tries to stay still. If this had been a freeze on the part of the director then fair enough, but it isn't as he and particularly Monica are still moving. It just looks rather corny and amateur, as though they are waiting for the "cut" to be called. (00:28:00)