It’s important for vote counts to to be independently checked. Having who voted publicly available means an investigative journalist can prove the county clerk’s claim that dead people voted and so they can’t certify the election is false. Or catch attempts at fraud. Both as a double-check on government in the case of officials who are lying or have acquired false beliefs, or as outside help if the issue isn’t caught internally due to under-resoucing.
He might have timed it that way (do it when he knew the assistant would be coming into the room shortly) on purpose to try to soften the blow to Aubrey.