Well it is a conclusion written without knowledge of signal analysis.
The input to the algorithm will be an image with a power spectrum that isn't natural, . It would be very natural even without "AI" to attempt to "deblur" when faced with such a power spectrum.
A deblur of noise can cause "hallucinations" with much simpler reasons than AI beong involved.
Could it not e.g. be doing some wavelet transforms or FFTs and automatic power spectrum calibration?
Continue to read through paragraphs 4 and 5 of the "Conclusion" section.