Factual error: The murderer works for a blood bank and drives a bloodmobile, a plot holdover from the first pilot ("Nick Knight"), which was set in Los Angeles. This second pilot, however, is set in Toronto - and Canada doesn't have mobile blood units.

Revealing: When Natalie shows Nick the murdered museum guard's bite wounds in the morgue, the "dead" man's carotid artery is pulsing quite healthily.