When Nemo drowns in his car, it would actually have been rather easy to escape, because once the car filled with water the pressure would have equalized, making opening the door no more difficult than usual.
After correctly stating that the left typing hand's home position is over A,S,D,F, the narrator then says that the right typing hand's home position is over H,J,K,L, but in reality it's over J,K,L & semicolon.
When Anna's moved with her father to Brooklyn, NY, and Nemo's mother has intercepted a letter she sent to him, the return address - which usually has some amount of 'genuine-ness' to it, in this case is far from reality. It would seem the return address was written by someone who didn't even attempt to simulate a real address for Anna, as it appears it's: ' Anna Vigo 139929 9th Ave. East, Brookland, NY, New York, USA, 43052'. ZIP codes in NYC all start with a '1', with the second number being a '0' , '1', or '2' (and, yes, 'Brooklyn' is misspelt as 'Brookland').
(around 2:24:51) the young Nemo, having ran into the forest and thus did not follow his mother to Canada, blows a leaf which leads to the adult him and Anna being reunited again at the lighthouse. However, this scenario is impossible because he only meets and falls in love with Anna if he moves to Canada with his mother.