Mistakes happen. In this case the authors report the issue publicly and should be commended for that.

The NeurIPS organizers can choose to address the issue in whatever way they deem appropriate, especially as the authors are not hiding the fact that their results were changed.

Of course you're free to assume it's malicious if you want (at least that seems to be the stance your taking, but if it's not then I might have misinterpreted your response).