This last election there were are fair number of folk who came into my polling place who were marked on the roster as “AV” (meaning “absentee voter”), but who claimed not to have received their absentee ballot.
Now I have not thought anything odd of this before. Perhaps the RoV (Registrar of Voters) mailed the ballot to the wrong address - voters move and often forget to notify the RoV. Perhaps the ballot was lost in the mail (though odds of this are probably low). Voters appear on the roster that have moved out or died (not unusual in number). Voters appear at the polling place who have moved in and believe they are registered, but are not on the roster (they are allowed to vote - tagged as “provisional” so the RoV will verify). The “absentee” voters may have misplaced their ballots. Collecting votes is not a perfect process, and you have to expect some human error.
Many of the “absentee” voters who show up at the polling place - saying they did not receive their ballot - are unsure if they can vote (they can). I have to assume a fair number of the “absentee” voters with lost ballots do not vote.
If you knew which voters you did not want to vote, and you could arrange to “lose” absentee ballots (anywhere between the RoV and where the voter picks up their mail) … you could probably change the election numbers somewhat.
More likely this was simple human error - but I cannot rule out the possibility of malice.