Continuity: The four souls on the bus board the bus in this order: Julia, Penny, Harrison, Milo. But when Penny boards the bus and walks to the back to sit down, the camera following her passes by a figure in a man's hat, sitting in the bus with his back to the window. This is exactly where Harrison is shown sitting later, wearing the same kind of hat, but Harrison wasn't on the bus when Penny got on.
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The four souls on the bus board the bus in this order: Julia, Penny, Harrison, Milo. But when Penny boards the bus and walks to the back to sit down, the camera following her passes by a figure in a man's hat, sitting in the bus with his back to the window. This is exactly where Harrison is shown sitting later, wearing the same kind of hat, but Harrison wasn't on the bus when Penny got on. See more...
Heart and Souls mistakes
Continuity: When the bus is coming to pick up Alfre Woodard as she is finally meeting her son, we see Robert Downey, Jr. briefly touch her on the shoulder. Since she's a soul, this is impossible.
Continuity: Towards the beginning of the movie, little Thomas is in the school restroom singing with his "imaginary friends." When he comes out of the stall to wash his hands he doesn't turn on the water but just rubs them under the spout and keeps on singing.