IT-anon here.
A couple of times today Ron has done this - ask a question that someone of his skillset should be able to answer.
I think this is deliberate to get other people to state it (so Ron isn't twatter-banned).
This question for instance: the answer is the 180 of what Ron suggests.
If you have a batch of ballots (say 50) you tell the machine I have 50 ballots.
It craps out on nr 26.
So as to not reset everything the force reset allows you to still scan the remaining 25 ballots.
However, if the machines craps out on a fixable error, the "bad" ballot can be rescanned, so the total scanned would show 51 not 50 as nr 26 was scanned twice.
But… it also means you could rescan the entire set of 50 ballots and hence generate 25 fraudlent votes.
So it's there for a legit reason (to help speed counting) since I suspect ballots are counted in batches far larger than 50.
It is also ripe for abuse.