Can an author claim future rights to an audio file marked as Creative Commons 0 License?

Question

Copyright

I want to use sounds from the freesound website in my game.
The name itself makes it clear that there is no need to pay there. In addition, on each page with an audio file there is an inscription: This work is licensed under the Creative Commons 0 License. Is it documented anywhere that a person has given his work (in this case, an audio file) into the public domain and he can no longer claim copyright (I'm not sure if I phrased it correctly, but I think the point is clear).
Suppose that the stars converged and my game shot, and the person whose sounds I used in my game found out about this and wanted money. Can he somehow fabricate evidence in his favor and win the trial? How safe is it to take audio content from such resources?
PS It seems to me that anyone can upload someone else'saudio file and issue it as a Creative Commons 0 License, and some developer may go to court. Is it so?