Continuity mistake: While Morgan and Prentiss are at the crime scene talking to the homeless man, when Morgan moves the tent and finds the text written on the wall, the homeless man smudges the text with his fingers, but when Morgan sends a photo of the evidence the smudges and text differ.
Add timeSuper Grover
Other mistake: JJ calls Hotch unsure if she can make direct contact with the unsub, fearing that she will make a mistake. Hotch tells her she will do fine and tells her that they are gathering background information about Flynn, who is the unsub. At this point the team have not yet figured out the identity of the unsub and Hotch should not know his name.