@uk

Not sure if this is helpful after it happens, but it may be useful going forward.

If you write a document that is your work, mail it to yourself via the postal service, it will then arrive at your address (or elsewhere) sealed and date stamped, keep this safe, if said document is ever plagiarized then this can be opened up in a court of law and a pristine document proving it was your work and the time frame it was created.

Not sure if this would still work.