Goofs

At the end of the episode Jane, her mom, and Maura are sitting in the bar when Maura's mother comes in. A waiter brings a milkshake to the people sitting at the table next to our ladies and they discuss their love of milkshakes. Less than a minute later as the camera pans out the "milkshake table" is now clean and the people gone.

Frost declares that he has found a second shell casing, but no first shell casing was shown to have been found.

The parrot is referred to as a "he" in numerous occasions. A true animal lover like Korsak would have known that it is actually a female as the patch above its beak is brown (female) and not blue (male). Budgerigars is one of the easiest species of parrots to separate male from female.

The bullet that Isles removes from the dead body is a centerfire rifle bullet that could not possibly have been fired from the .22 rimfire AR-7.

Colonial women weren't slaves, that's what the Africans, Irish, and Scottish were for. (The English were equal opportunity enslavers.)

Maura says that the professor's accent is authentic to colonial times. She goes on to say that Americans at the time spoke a "rhotic English in a variety of regional dialects; Scotch-Irish, West Country." Only one, single, point of this is correct, and most of it doesn't even make sense. The correct point was that the Scottish and West Country accents are rhotic. What she got wrong was: The professor's fake accent is the American version of a modern, posh English accent; so it's from the wrong century, and nothing like the Scottish, Irish, or West Country accents. "Rhotic" means an English dialect, so "rhotic English" is a tautology, and "rhotic English dialect" is so absurd there's no word for it. There is no such thing as Scotch-Irish they're different countries, separated by a sea, they don't share either accents or dialects. And the colonists (the Pilgrims) mostly came from the Midlands, which is miles away from the West Country and the accents aren't remotely similar.

A smithy is a building, not a person. It's a blacksmith's workshop, the person who works in it is a blacksmith, or just a smith. A smith is anyone who works with metal.

After Rizzolli asks why the sniper fired only one shot, Frost declares that he found a "second shell casing," but he picks up a loaded round (case and bullet) and not a shell casing (the remaining empty case after the bullet is fired). Having been trained in using firearms, a police officer would surely know the difference.

When Korsak concludes that the shooter must have ceased firing because of a stovepipe jam, his reasoning is badly flawed. A stovepipe jam occurs when a shell casing gets stuck in the ejection mechanism and prevents the next round from loading properly. If a damaged shell casing or loaded round was found on the ground, this indicates that the shooter presumably cleared the jam and reloaded the firearm successfully, and therefore must have ceased firing for some other reason.

When Frost, Korsak, and Rizzoli watch the surveillance footage of the 2 white Chevrolets, the cars are 2 different models; the one on the left is a Cobalt, whereas the one on the right is a Sonic.

Dr Isles says that a parakeet died of avian flu but says there's no risk to humans unless they ingest the bird's feces or give it mouth-to-mouth. All forms of flu including avian are respiratory diseases, infecting the lungs. Avian flu is transmitted when drops of bodily fluid from the birds or dust from their feces is inhaled (not ingested) or comes into contact with the eyes.

Although it is acceptable now, "excusez moi" wasn't used by the French when Isles learned the language. She should have used "pardon moi".