For me it's one in Gilmore Girls
It's established canon that Lorelei ran away at age 16, and has lived in Stars Hollow for 15 years.
It is also established canon that Lorelei can't cook and has basically relied on Luke to feed her child since she was small.
An ex girlfriend of Luke's is introduced to the show, despite the fact she has lived in the small town before and dated the guy whose cafe Lorelei practically lives in, she has apparently never met or even heard of this woman who the entire town knows well.
It doesn't add up
(I overanalyse Gilmore Girls massively all the time, I find the psychology really interesting Lorelei is blatantly an antihero masquerading as a hero)
