You're right in that the election fraud is a math issue, but it is also a data science issue. The original post is probably referring to the discrepancy between the publicly available data from the Pennsylvania voter registry and the number of votes. If I recall correctly, the Secretary of State claims that the voter registry data is incorrect, but, last I checked, they were refusing to release the correct data that could prove the allegation wrong.

Let me know if you find something different about this case.