When John and Alice are in the library, Alice rips a page out of the "Magical Objects and Potions" book while John is distracted. He then begins to read about some dangers of the teapot on the lower right edge of the right-side page. Turning the page he cannot keep reading because the next page had been removed. In reality, the continuation would have been on the upper-left back side of the page he turned, which was clearly full of text.
During one scene when Alice and John are in bed after taking the teapot, the clock changes time from 2.46 to 2.34 vice versa add a minute or two, between each of the different shots.
The check at the end for $250,000 has a routing number (90162537) of eight digits. Modern routing numbers always have nine digits, just like Social Security and Taxpayer Identification Numbers.
When John and Alice are in the library, Alice rips a page out of the "Magical Objects and Potions" book. When John first notices, there are certain pages to the left and right of the torn out one. In the next shot with John, they are totally different pages with the torn page still in the middle.
The bill at the restaurant has several numerical errors. The two coffees are shown at $2.23 each with a total of $8.75. The total of the individual items is $706.75, which does not match any of the subtotals further down. The two subtotals plus the tax figure add up to $1020.55, which does not match the amount due figure of $974.75.
During the continuation of the "psychological warfare" sequence in the kitchen, the reflective edge of the table reveals the feet of the crew.