Factual error: At the beginning of the episode it is stated that we are in the month of April - yet in the orchard there are ladders, fallen apples and baskets filled with fresh fruit everywhere, as if it were harvest time. The god is declared to grant fertility and not climate change, so the harvest decoration seems definitely out of season.
Factual error: When the doctor says that the dead man has a high lymphocyte percentage indicating a viral infection after she looks down the microscope: 1) What they show in the microscope looks nothing like what is actually visible down a light microscope (especially the supposed lymphocytes) and 2) Even if she could see what they showed, it wouldn't actually indicate that the infection was viral.
Factual error: When Sam and Dean show up at the crime scene to investigate, they are stopped by a woman wearing digital Army ACU's. She introduces herself as Sergeant Miranda Bates, even though she has rank insignia on her cover and her chest that identifies her as a PFC (private first class).
Factual error: The man gets hit hard enough by the bus to knock his shoe clear off, yet when we see his body about to be covered up, there's only a small amount of blood on his mouth. If you get hit by a bus hard enough to make your shoe fly off, then there should have been more damage.