I did not see it directly but I saw some things that did not pass the straight face test and could not account for two of the people after the doors closed. It is just from my experience in intel with the military, my ability to observe is still sharp. While working the sign-in tables I was able to see just how easily it could be done.
Just as I thought, the extra voting goes on after the polls close so there are fewer people to witness it. Having been an election judge, I know people are happy to go home after a14 hour day, leaving it to the two chief judges to finish up and take the ballots to election headquarters. One is supposed to be from each major party, but there are lots of inner city precincts where two Dems have both of these positions. No wonder so many Dem cities report their totals late.