“In actuality, Karpinski said, what the clip captured was the canvass worker darkening an oval that had been filled in too lightly, to ensure that it would be picked up by the ballot scanners.”
That IS ballot tampering.
What if someone had changed his mind about the vote or lightly marked on accident (dropped their pen, ink smudge from their hand, etc).
HE essentially took a vote away from Trump. It's an old trick.
This is why there should be NO writing anything on the ballots. No writing tools at all in the room!! If the mark is too light, too bad.