Continuity mistake: In the flashback, the level of whiskey in the bottle changes from 1/3 empty to nearly full and back again as the shots alternate. (00:16:25)
Continuity mistake: While the doctor is playing the tape for Reese, Nick and Tracy, the Toronto Leafs hockey team coffee cup on Reese's desk is sitting with the leaf logo turned away from the camera and the hockey player art showing. A few shots later, though Reese isn't drinking any coffee and hasn't touched it, the cup turns itself so the leaf logo is now visible. A little later, it's turned back again. (00:22:30)
Continuity mistake: Nick gets a phone call telling him another murder victim has been found and that she's been dead for at least a week. In the very next scene, Schanke says that the victim "disappeared after a date last night." (00:27:00)
Continuity mistake: When Nick breaks into the old Chinese herbalist's warehouse, he twists and breaks a doorknob lock. But when he walks through to the inside, there's a latch-and-bar array instead of a knob. It's a completely different door.
Close Call - S2-E25
Continuity mistake: In the establishing shot of the epilogue, it's 9:10 on the clock outside the station. But in the very next shot, it's 7:10 on the clock inside. (00:42:20)
Near Death - S2-E23
Continuity mistake: The flashbacks here recount Nick's "bringing across." But for the second time in the series, the recap of this event contradicts the original pilot film version in that the characters have all changed costumes. (00:25:10)
Near Death - S2-E23
Continuity mistake: While Nick is interviewing Dr. Linsman, the position of his hands shifts (from lying flat on the desk to held up near his face) every time the camera angle changes. (00:08:15)
Continuity mistake: The wooden plank with which Alexandra impales Nick completely changes angles (from flat side tilted left to flat side tilted right) between the time it strikes him and the time he pulls it out. It also appears to "grow" an inch or so wider than it was before. (00:39:00 - 00:40:25)
Continuity mistake: The tow truck and the red van it's towing change positions at the alley's entrance between shots. (00:01:00 - 00:23:35)
Continuity mistake: The clock on Natalie's lab wall jumps forward almost half an hour during a 2-minute conversation with Nick. (00:27:25 - 00:29:05)
Close Call - S2-E25
Continuity mistake: Though the camera angle doesn't change, the brightly lit Chinese-character sign on the wall outside the window moves several feet to the right between takes. (00:09:10)
Crazy Love - S2-E26
Continuity mistake: The flashbacks here contradict series canon. Nick's victim, Amaya, is shown to have been bitten (by him) several times. In every other instance, unless he had multiple captive ladies to "sip" from, Nick's bite was fatal in one go. In fact, it was a major recurring plot point that Nick "couldn't stop."
Partners of the Month - S2-E18
Continuity mistake: Schanke's mother-in-law had previously been established as dead, yet Schanke's talking to her on the phone in this episode. (00:16:25)
Father's Day - S2-E7
Continuity mistake: The godfather's thugs storm Nick's loft and riddle him with bullets. We actually see the bullets coming out of his back, leaving holes in the back of the vest he wears. But when the "vamped out" Nick turns around to face the camera, there are no bullet holes in the front of his vest. (00:23:20)
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.