In the recent SO moderator election, OpaVote says that there were 28331 ballots. Downloading the .blt file from OpaVote and summing the vote weight also results in a total vote weight of 28331 as expected. But downloading the .blt file from the election page on SO tells a different story: that .blt has 28328 votes in it: it seems 3 votes are missing. The file has 28338 lines, with 1 ballot per line, but 10 of those lines are metadata and not votes, leaving a mere 28328 votes in it. Here are the scripts I used to get those numbers.
Specifically, here are the votes in the OpaVote file missing from the SO file (this is a bit complicated to get since the SO file has 1 vote per line but the OpaVote one lumps identical votes together):
1 1 0 # Zoe1 6 2 4 5 1 0 # Dharman, Ryan M, Daniel Widdis, Stephen Rauch, Zoe1 1 2 6 4 5 0 # Zoe, Ryan M, Dharman, Daniel Widdis, Stephen RauchWhat happened to these three votes in the SO file? Perhaps they deleted their account and that deleted their vote too? Perhaps there was a race condition where 3 people voted in between the generation of the two files? Regardless, the ballot file from OpaVote and the election page should always be semantically equivalent. This might be a regression of a similar fixed bug from 2012.
Note that the election page itself says "28,754 voted", which is more than any of the above numbers. This is not a bug, since that bigger number also seems to include people who voted for nobody, and those people don't get included in the BLT files (except they actually do if they exclusively voted for candidates that were removed mid-election).