Parenthood - S2-E14
Continuity mistake: In his office with Garrett, Frank reaches for his cup of coffee twice, and moves his foil-wrapped breakfast sandwich from the top of a stack of blue folders to the top of a newspaper. However, in the next shot, the egg sandwich is back on top of the stack of blue folders. (00:06:15)
Answer: It's a common cop show plot device. If the police on the show always acted in the most logical way (i.e. not alerting a suspect to their presence) the show wouldn't have the opportunity for an exciting foot chase.