Continuity mistake: When it shows the plane flying to London, in the first shot we see it is a huge craft but when it shows the inside it is very tightly compact and narrow.
Revealing mistake: During the big fight between Peter and Hook, Hook scratches Peter on the arm with his hook. If you look closely when this happens, you can see the hook bend on Peter's arm, a rubber hook with fake blood on it to make a realistic scratch.
Continuity mistake: When Peter's daughter shows the drawing on the plane, he asks "where is my parachute? A shot later the girl disappears.
Visible crew/equipment: White lighting screens are reflected on Peter's glasses when he looks up to see Rufio for the first time, and right afterwards when he runs away and bumps into a net.
Visible crew/equipment: When the assistant shows up to film Jack, the studio lights reflect on his glasses.
Continuity mistake: The golden sword of the Pan gets a lot of use in the final fight scenes. A lot of shots show that the sword gets tiny notches on the sides from all of the clanging against things. However, when Peter passes the sword to the large Lost Boy, the sword's edges have been beveled smooth.
Continuity mistake: During the school play, Peter's phone rings and his wife turns her head to him. When the shot changes she's looking straight and turning her head again.
Continuity mistake: When the phone is thrown outside & later dug up it is clearly a dummy (fake) phone.
Revealing mistake: When the kids are having the big battle with the pirates on the ship, they have that gun that shoots out eggs. You can very easily tell that in one shot there is a fake rubber chicken in the basket on the top, and in the very next shot it is a big fat live chicken.
Continuity mistake: When Peter recalls himself alone in the rain with a teddy bear by his side, the bear is sitting upright in the first shot, but resting against the baby with its head skewed in the following angle.
Continuity mistake: Peter is lying in the cradle with Tinkerbell flying around, the fluttering of her wings making his hair messy. When he stands up his hair is neatly brushed to the right.
Continuity mistake: After Jack removes his Hook-styled wig his hair is messy and caked. Then the fight starts and the next time we see him his hair is shorter, cleaner and perfectly brushed.
Continuity mistake: During the insult war the black kid next to Peter leans forward and fakes a puke. When the shot changes he's sitting still.
Continuity mistake: The green haired mermaid is very close to Peter, but a shot later she is far away, swimming towards him.
Continuity mistake: In the plane, the way the note book is held changes between shots: by the top or by its side.
Continuity mistake: When a lost boy fires balls at the pirates, they slip and fall on the deck. Angle cuts back to the boy firing and the deck is suddenly spotless and empty, and the same pirates repeat the previous actions.
Continuity mistake: When Pan is about to kill Hook and his daughter grabs his arm and says "Please daddy, let's go home", Pan's arm swaps from bent to straight between shots.
Character mistake: When Hook has Pan under control, the kids start to say "I believe in you" in turns. The second one, a red haired boy, can't help staring at the camera.
Revealing mistake: When Peter sees Tink in a night dress, the shots from behind reveal an obvious doll. Note how it does not have any fluffy hair (or any hair at all) as opposed to Tink's.
Continuity mistake: When Hook and Peter's battle starts, Hook's sword falls on the floor. Its position changes between shots.
Answer: Neverland very much runs on "If you believe, it will happen" which is what Tink means during the meal when she says "If you don't imagine yourself as Peter Pan you won't be Peter Pan." So by the rules of Neverland, as soon as Peter believed it was real it was then real. The dinner was trying to teach him to believe as, in Neverland, if you don't believe it then it won't happen.