When Hodgins accidentally kicks the pumpkin into the coffin it lands right-side-up so that it is at a 90 degree angle to the prone corpse. When the view changes to an overhead shot, the pumpkin is now facing straight up, meaning that it has somehow rotated 90 degrees and is now lying on its side.
The tooth in the porcelain fragments is a lower incisor not a canine tooth.
When they examine the ancient book Hodgins realizes that in order to see hidden text they need candle light to "illuminate" it. Angela quickly brings up an image of a flickering candle on a monitor to provide the needed lighting. However, the light spectrum of a real candle would be completely different from the light spectrum of a television image. (It's surprising that Brennan, who corrects people on even the smallest mistake didn't point this out).
When Dr. Soroyan brought the severed ear to Angela and tells her that the victim also had purple hair, Angela goes and updates her artistic recreation of the victim. She takes the reconstruction she already had and changes the hair color and since the ear showed she had ear piercings, randomly adds several piercings on her face. She then sends the reconstruction photo through facial recognition, and finds a picture of the victim. The photo of the victim has piercings at the same place as Angela's reconstruction, but the stud placement was supposed to be random since she couldn't have know where they were on the victim's face.
In the season premiere of season 9, Hodgins mentions to Angela having Sleepy Hollow on DVR (the series premiere of Sleepy Hollow was airing right after the season premiere of Bones.) Now the characters from Sleepy Hollow are interacting with the characters from Bones, so Sleepy Hollow shouldn't be a show in their world.
At the end of the episode, while Booth is interrogating the boyfriend, the boyfriend says he wants a lawyer. This is where the questioning must stop. Anything obtained from this interrogation (confession) is inadmissible, as it is a violation of Miranda.