The area code for Harrison's phone is 305, which is a Miami, Florida, area code. Before journeying up to New York, Harrison was in the Florida foster care system. So of course the cell phone he's had since that time would have a Miami, Florida, area code.
When Dexter is kidnapped and being transported to Kurt, two different trucks are used. The truck while driving has a different grille than the one that crashes.
At the end of the episode, Angela finds a web page about the Bay Harbor Butcher that states that ketamine was used to sedate the victims. This is untrue. At the time, Dexter was using M99 or Etorphine, a semi-synthetic opioid, to sedate his victims in order to capture them. He only used ketamine now as it was easily accessible. Angela's search for "ketamine Miami Homicide" should have yielded little to no results.
After stopping Elric, Dexter takes his hat--apparently to disguise himself as Elric in order to get closer to Kurt. However, when he is driving towards Kurt, and the disguise is supposed to benefit him, Dexter needlessly removes the hat, only revealing himself to Kurt and preventing himself from stopping Kurt.