Patzer

In Season 1, it is mentioned that Donnie and Alison were high school sweethearts, but in later seasons that are described as meeting in college.

Beth's Jaguar X-Type changes specification throughout series 1. The Interior often changes from an early car to a later car throughout the the series. Notably the design of the front seat head restraints change design and the steering wheel changes from an all leather rim to a maple wood rim which also features a completely different design of wheel centre.

In season 1, Cosima confidently refers to the clone experiment being "double blind." However, this is a factual mistake. A double blind experiment is designed such that neither the participants nor the investigators know which participants belong to the test group(s) versus which participants belong to the control group. If this were a double blind experiment, Cosima would have no way of knowing unless she had designed the experiment herself. She would also know that a double blind design requires a control group, whose existence she would likely seek.

More likely is that the experiment is single blind, where the participants do not know the group(s) to which they belong, but the investigators do know. However, once again, Cosima would have no way of knowing this information about the study design unless she were herself an investigator. As a graduate student scientist, realistically, she would at least know the difference between a double blind and single blind design.

The equivalent of "Helena" or "Helen" in most Slavic languages, including Ukrainian, has no H.

Cosima mentions in season 1 that Katja's fingerprints would be close enough to Sarah's that running Katja's prints through standard police search would pull up Sarah's rap-sheet. No one seems worried that Beth's fingerprints should have been just as similar, and as a police officer her prints would definitely be in the system. Why didn't Sarah's rap-sheet emerge when Beth applied to become a police officer? Why did the system match Katja to Sarah but not to Beth? The system may have matched Sarah to Beth, but other data would not have matched, such as date of birth, place of birth, parents etc. The match would have been seen as a false positive which often occurs in fingerprint matching systems. Even in ten-print matches, depending on what level of search was employed. In many systems, technician intervention is required to eliminate candidate matches.