Again, that just seems like a really odd/obvious way to cheat, and very easy to catch. Those totals come from precincts, and the precinct numbers all have to add up to the final total in the end. So if there is cheating, it is almost certainly happening in the precinct level. Or at least the county level for mail-in votes.
That kind of deliberate fraud is just to easy to track and correct.
So what you’re saying is that the error of adding votes to the wrong candidate occurred at some time before the initial vote totals shown in the video, and the plus/minus update was a correction that was made once someone realized their mistake.
That sounds plausible.