Do you have a link where he alleges the tampering? I'd be interested to learn more. I should try to find the court documents, usually available through a PACER-type thing for a nonzero but modest charge.
It's quite a long video, I can not claim to have seen it all, but the allegations should come up within the first 36 minutes and after the initial introduction by the third party.
https://www.youtube.com/watch?v=S7hnVYMoctM
EDIT: The court documents were linked in another comment, I relink it: https://blogs.microsoft.com/uploads/prod/sites/5/2018/04/FIN...