I don't trust their exif, and we are no longer looking at the IR sources. The EXIF data has been edited, so that the lens says the Sigma 50, but at 70mm and the filename is a name that cannot be set in the camera.
Now we have our own samples to work with. And we have DPP that can work with the raws. Finally, we can now do our sharpness tests. This particular thread is purely about ISO and not sharpness/details, as Jim pointed out.
DPP 4.1 recognized the lens as the EF-s 50/2.5 macro and offered to download the lens profile for it. I agree that I do not trust the EXIF either.