Have you run the walk-through to reproduce? They provide a highly detailed step by step document. They welcome raising an issue if reproduction doesn't yield the claimed results within 2%.
It's OK to call out fake claims. But it requires going through the process if such is reasonable, it just seems to take a couple of hours to find out.
The fake claim here is compression. The results in the repo are likely real, but they're done by running the full transformer teacher model every time. This doesn't achieve anything novel.