When Mrs. Bennet is dialing you can see Sylar's hand in the background as he lifts his finger. But in the next shot he lifts his finger again and the phone is finally thrown out of Mrs. Bennet's hand.
In the opening scene, Peter and Claude are walking down a busy sidewalk, their characters are supposed to be invisible. (Claude is bumping into unsuspecting pedestrians, stealing scarves, etc.) Yet their reflections are visible in the windows they pass.
When Hiro is talking to his father and telling him that Kimiko would be a better heir than him; Hiro bows to his father and in the background you can see someone start to slide the door open and then close it quickly.
After Micah asks his mother to play scrabble, towards the end of the episode, as the camera pans across Nikki's back towards the "S" tattoo, the camera crew can be seen on the right hand side mirror quite clearly.
There are no mountains in Odessa. It is located in the South Plains region of the country.
Claire tells her mom that she would be home from Lubbock in an hour. The distance from Lubbock requires a two hour drive. Any Odessa resident would know this, even a ditzy mom.