Checkie pulls per lever too far back, disabling autofeather and increasing actual min control speed. 25.149 from memory talks about vmc being certified with auto feather.
It's been over a decade since I have flown a turbo prop and that was a Dash not the E120, however I suspect the auto feather system would be similar to the Dash. (same engine prop combo as the Dash 100)
The auto feather isn't activated when simulating an engine failure by moving the thrust lever.
There were other requirements to make it auto feather, and I can't recall what they were. So the way I read it, the check pilot reduced the thrust below the zero thrust setting which creates extra drag and isn't an accurate simulation of auto feather, which in turn increases VMCa.