In response to Beth's query about what "10 to the minus 39th power" means, Adam states that it is the number represented by a decimal point followed by 39 zeros followed by a "1". Actually, it is the number represented by a decimal point followed by 38 zeros followed by a "1".
When Beth has her picture hanging up inside Adam's closet, he turns around to look at her and the clock next to Beth says 10:40. Then Adam looks at the picture again in confusion then looks at Beth again a few seconds later and the clock next to Beth then reads 10:39.
The goof item below may give away important plot points.
Adam's interview is on February 3, and Marty plea-bargains with the court the same day. His sentencing hearing is the next day, which would make it February 4. The judge tells Marty he has one week to settle his affairs, but tells him to report to prison on Monday, February 9 (five days). Even without taking the interview date into account, this still doesn't make sense, because it would mean Marty's plea-bargain with the court took place on February 1 - a Sunday, when court is not in session.