Were they just mail-in and not absentee. Absentee requires a request for the ballot and a chain of custody, mail-in are just sent whenever to whoever without verifying where a voter lives (or if they still live).
The mail-in still have a record of being sent, and a record of being received back. That's where they saw the discrepancy - 74k more received records were found than sent records, when, even at 100% voter response, the numbers should match. And realistically, you'd have significantly less received votes than sent votes.
Were they just mail-in and not absentee. Absentee requires a request for the ballot and a chain of custody, mail-in are just sent whenever to whoever without verifying where a voter lives (or if they still live).
The mail-in still have a record of being sent, and a record of being received back. That's where they saw the discrepancy - 74k more received records were found than sent records, when, even at 100% voter response, the numbers should match. And realistically, you'd have significantly less received votes than sent votes.