Towards the end of the episode, when Jane and Mr. Harrington are playing a board game and talking, in the mirror on the wall behind them, you see Rigsby adjust his suit jacket. Cut to Rigsby on the couch with the little girl and his arm is hanging straight out off the arm of the couch. Cut real quick back to Jane and you can see Rigsby still adjusting his suit jacket in the mirror messing with his jacket.
When Patrick Jane and Agent Cho go to Visualize for the very first time, the location and city are not shown as captions at the beginning of the scene as is normally done for every location featured in an episode.
Starting at 10:14 when Rigsby and Van Pelt are interviewing Ed while he gets a massage, a large black hair can be seen on the bottom of the screen approximately 1/4 way from the left-hand side. The hair disappears around 10:18 when it cuts away, but another hair is visible again even further to the left at 10:22.
The first suspect occurs when Jane notices blood on someone's shoe. Had she stepped in the blood (which is later shown in a flashback) she would have left at least one bloody footprint on the carpet, and no one seemed to have noticed this when they examined the crime scene.