Factual error: As the creepy "Nightcrawler," master vampire LaCroix taunts Nick via his CERK radio broadcasts, which Nick listens to on his Cadillac's car radio. Except, CERK's studio sign says it's an FM station. And Nick's Caddy, supposedly a '62, still has its factory radio (we get lots of good close-ups of that), which in 1962 was strictly AM. So how was he receiving LaCroix's station?
Factual error: Though she wore medical smocks and occasionally a baseball cap to hold back her hair, Natalie was never correctly attired when she performed her autopsies. In fact, she usually worked with her hair loose and hanging down over the corpse, which may have made her look prettier, but is a serious breach of forensic etiquette that could contaminate the evidence. Even the best-coiffed coroners still have to wear sterile caps and gear.
Factual error: The police call-radio added on to Nick's old Cadillac (along with a handy dandy detachable dashboard police light and a siren) somehow managed to work for all 3 seasons without an antenna.
Factual error: The Cadillacs (all three of them) used throughout the series to play the part of Nick's sea-green, large-trunk vampire transportation were not, as claimed in the show, 1962 models. Nick's car, in all its incarnations, was actually a '61.
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. (00:31:35)
Factual error: The murder victims, all Catholic, are specifically said to have "all worn crucifixes." But the jewelry Nat hands Nick as evidence, the cross that burns his hand and the necklace Magda later gives him are all plain crosses, not crucifixes. (The former is unadorned; the latter has a Christ figure on it.)
Factual error: Vampire Erica commits suicide by sitting on a park bench at sunrise. Nick and Schanke are called to the scene only a short time later, or so we're led to believe, yet it's still fully dark when they arrive. No sunrise in sight. (00:01:00 - 00:05:30)
Factual error: The doll that supposedly belonged to Erica 300 years ago is too obviously modern, with a plastic head and body and nylon hair.
Spin Doctor - S1-E15
Factual error: Nick tells Nat about his past life as an assistant professor in the U.S., and refers to himself as "a certain indigenous vampire." Nick wasn't indigenous (native) to either the US or Canada, where the show was set. He came from Brabant, now part of Belgium. They were probably trying for "itinerant" (wandering), which would accurately describe Nick's long life.
Factual error: In the flashback, when Nick regenerates on the autopsy table, his shredded clothes repair themselves, too. Maybe Nick buys his outfits in the same place the Incredible Hulk does.
Factual error: Nick's '62 Cadillac had an attached police radio, but never had a car phone, nor the giant external antenna attachment they required in the early 90s. Yet Schanke somehow makes a call from Nick's "car phone" in this episode.
Factual error: The supposed ballerina in this episode's flashback to 19th century France is not employing any real ballet steps or arm movements. All she's doing on stage is standing still and waving her arms in the air, performing something that looks rather more like semaphore than ballet. (00:10:10)
Factual error: The cop who arrests Nick reads him his Miranda rights ("You have the right to remain silent," etc.) But "Forever Knight" is set in Toronto. At last report, Toronto rather resolutely insists upon remaining in the sovereign nation of Canada, where the Miranda Act, a U.S. Federal law, is not observed. (00:14:40)
Factual error: Nick tells fellow vampire Aristotle, "You still owe me for that time at the Battle of Hastings." Nick was brought across in 1228, or so the intro told us every week. The Battle of Hastings, as any British school kid knows, was fought in 1066, over 100 years before Nick's mortal birth. (00:29:30)
Factual error: Nat's god-daughter Cynthia Luce is buried within a few days of her murder with an elaborate headstone already in place. (In reality, headstones take months to produce.) But the wrong name is carved on the stone. It reads "In memory of Cynthia Lambert." (00:43:30)
Factual error: At the very end, Bridget Hellman is buried with a fully-engraved headstone in one just one day's time (which happens only in tv & movies: the process takes months in real life... er, death). She also spontaneously returns as a vampire without being "brought across," a violation of series canon, and she comes back mysteriously sporting 3 times more hair than she had as a mortal. (00:43:10)
A More Permanent Hell - S2-E20
Factual error: In the first scene, Dr. Dana says the asteroid heading for Earth is 5 miles wide, "larger than the one that caused the dinosaur extinction." The asteroid that did in the dinos is estimated by most scientists to have been 6-8 miles wide. (00:03:00)
Crazy Love - S2-E26
Factual error: Dr. Shawna Welsh's medical degree, visible on the office wall behind her while she talks to Nick, misspells the name of Johns Hopkins Medical College as "John Hopkins." (00:08:35)
Factual error: In the flashbacks, the shipboard lifesaver rings are emblazoned with the incorrect designation "S.S. Titanic." The Titanic was a Royal Mail Ship. The stencil should have read R.M.S., not S.S. (00:14:00 - 00:24:50)
Factual error: When the Inca is threatening Tracy in Spanish, the translation subtitles read, "He thinks he has invaded me." They were supposed to say, "_evaded_ me." (Note: This has been corrected in the dvd set released 10/06.) (00:41:00)
Answer: Nick was sick and tired of being an immortal bloodsucker. He wanted to be human, fall in love, get married, have children, grow old and die. As for Janette, according to her, she fell in love and the passion she felt "cured" her of her blood lust.