A manual recount was performed, and during the manual recount election workers "found" a bunch of ballots

This is exactly what happened with the Santa Clara County (CA, USA) transit tax a few years ago. It initially failed by several hundred votes (2/3 majority was needed). Over the next few weeks, they kept "finding" additional ballots, and every batch had disproportionately high Yes vote percentages on the measure (although all other races were unaffected). Then the second they reached the needed threshold, they conveniently stopped finding ballots.