In the final scene the position of Marilee's hair changes depending on the camera angle. In camera shots looking over her shoulder at his face it is tucked behind her ears, but in shots looking over his shoulder at her face it is hanging down in front of her ears.
When the fire engine pulls out of the station in one of the opening scenes, it doesn't have any hose in its bed.
Outside the fire station, Marilee's lipstick is pink. In the next shot, inside the fire station, her lipstick is red.
While at the taco stand, all the people in line are wearing heavy winter jackets, hats, and gloves. The lead character is in a skimpy dress without a coat nor is the fireman wearing one.
Throughout the movie it is suggested that mountain lions mate for life, which is not true.
Marilee hangs holly not mistletoe up. Mistletoe has white berries not red.
Evictions do not work the way portrayed in the movie. Marilee is told by her landlady that if she finds a cat it would mean immediate eviction, later when Queenie is discovered, she moves out that minute, going to stay at Zachary's house, suspending belief that any woman would do such a thing in this day & age, an eviction must go through a court system & there usually is a 30 day notice given. No one would be kicked out immediately.
Sarah gives her age as "almost 79 years old," ostensibly in "dog years." However, if she were almost 79 in dog years, she would only be about 11 in human years.
When Zachary gives Ambrose milk, it is a common misconception that cats should be given milk regularly as a treat. The truth is that most cats are lactose intolerant so giving them cow's milk can actually cause GI upset like vomiting or diarrhea.
Right after the photo shoot when they getting in the firetruck Zach says to Mark you're married and Mark says they don't know that. Mark is clearly wearing a wedding band.
The two main characters meet in the grocery store for the first time, Zachery deciding on cat food. The first thing Merilee asks is, "What kind of cat is he?" It should have been, "What kind of cat is it?"