In the cafeteria, Leonard says that Sheldon goes to the bathroom at 8:00 AM with optional follow up at 1:45 PM however in Season 2's The Monopolar Expedition (2009), Sheldon says that everyone at the university knows that he has breakfast at 8:00 AM and moves his bowels at 8:20 AM.
After Howard explains about the camera being from the Mars Rover, he rolls his lower lip back and starts to stick out his tongue. In the next shot, his lip is out and his tongue is not showing.
Howard and Raj are whispering outside the basement door while Sheldon is on the other side. Sheldon's acute hearing has been noted quite often, but this is not a goof - nothing indicates that he hasn't heard the whispers. Quite the contrary, he remains quiet (Howard and Raj don't hear his antics with the hacky sack) and immediately notices when his friends install the hidden camera. Everything indicates that he was aware he was being spied upon.
In the past, Sheldon has been shown to be completely uncoordinated when it comes to any type of sport, yet he is able to keep a hacky sack in the air for a count of 43. Sheldon's abilities improve (albeit slowly) throughout the series; using the hacky sack in complete secrecy to improve coordination is in line with this.