When the unsub enters the building where the meth dealers are, he has both hands in the pockets of his coat, but when Hotch and Blake are looking at the surveillance video, he has a gun in his right hand.
The surveillance camera shows Walsh's SUV has a Florida license plate on the front. Florida only issues a rear license plate.
When the unsub shoots the abusive ex-husband, only the second shot is seen with a muzzle flash but not the first or third shot (10:40). The gunshot sound is heard for all three.
When Reid is counting the number of days and mentions 2008 as a leap year, the captions show 2009.
Reid makes a mistake when calculating the dates using the numbers found in the black book. It is correct that there are 87 days from January 14th, 2014 to April 11th, but 3553 days before April 11th is July 19th, 2004, not April 9th (that is 3654 days).