The problem is that the altered images represent a still plausible theory. There is a reason why they were believed in the first place. It isn’t that these false images are negative evidence. Instead, they don’t help or refute the underlying hypothesis at all.
The real question (that I’m not sure about) is if anyone else has been able for replicate the original experiment.
I get that it is complicated but fraud in one area (images) makes the hard data extremely suspect.