Actually, it is a mathematical likelihood. Overall the national reduction was between 0.8% to 1.4%…. A difference of 0.6%… that is not unusual.
This actually has no indication of ballot box stuffing. It is only a measurement of rejected ballots. Ballots may be rejected for many of reasons. Chief among them are minor errors to follow the directions. Any situation of ballot duplication or otherwise fraudulent ballots are reviewed and most are disqualified.
True, the system isn’t perfect but a decimal percentage of valid votes failed to count to invalid votes getting through do not usually make much of a difference anyway. And states where the vote is close enough that they would, are better scrutinized in the recounting process.
So no, it’s not an indicator of ballot stuffing nor does it put in dispute that the election wasn’t as secure as was claimed.