Plot hole: When Mr. Jeffries finds out that Evan is named August Rush too, he goes to the Central Park concert and sees Evan onstage, however he couldn't know that Evan was having a concert, or even that Evan was at that place at that time.
Suggested correction: There were streetlight banners all over Central Park with August Rush's name on them (and presumably the Philharmonic had flyers and other ads with August's name on them). So it's certainly conceivable that Jeffries recognized the name from an advertisement.
Plot hole: 12 years have passed through the entire movie since the beginning where Lewis and Lyla first meet to the end when they together discover their now 11-year old son. However, neither Lewis nor Lyla look like they aged whatsoever in 12 years.
