There is a copy on the internet of the 2020 syllabus as well as an undated syllabus. They are on a "membership" site.Do you gave a copy of the syllabus?
None of us know what the Fall 2022 syllabi for Snyder's courses said. But I think if the disgruntled students had been following a grading rubric on the syllabus or one otherwise provided by the professor, it would be logical to complain if the TA wasn't following that rubric. Students usually cling to syllabus language if it seems to support their position. Admittedly not that many students have spoken up but no one has said BK wasn't following published grading standards. They just said his standards were too high. So I do suspect there weren't published standards provided.
JMO