That would be pretty straightforward to dismiss with full transparency by the alleged perpetrator. There's definitely going to be corroborating evidence.
Oh, absolutely. I guess I was wondering if accusations alone would serve to substantially inconvenience or embitter individual scientists, or decrease public trust in academic research and academicians in general. Not trying to suggest that this case specifically is some foreign plot.
Not if that full transparency uncovered further forged documents which corroborated the accusations. If we're assuming a full on intelligence operation here then that wouldn't be significantly harder to pull off. After a couple more pieces of evidence the story would support itself and any inconsistencies would be blamed on the target's own attempts to cover up.