I agree on it not being uncommon. I ran across a bunch of weird results from Charlton last night that had a similar issue, except there were errors in both the unofficial results (since updated) and the map results in different places. It gave 5000-1 result for one of the questions, which is a lot more obvious than this sort of error.

It’s just tough to perfectly parse this much data from this many towns and hard to find errors like this unless you’re specifically looking for specific weirdness in a particular area on a particular question. It all gets cleared up for the official results, so it’s just a matter of slightly annoying us impatient people who need our data now.