Northampton County PA held a county election November 5, 2019, using "ExpressVoteXL" voting machines, supplied by Election Systems and Software. These machines were delivered in August 2019, and conformed to federal and state performance standards for voting machines, according to a report in the New York Times, 12-1-2019.
(There are roughly 6,300 ExpressVoteXL voting machines in use around the country, and reportedly none of them have had problems with counting votes.)
The machine tallies votes instantly and also prints a paper backup ballot when each elector casts his or her ballot.
The total of the instant results in the County Judge race were:
Kassis (D) 164
Scomilio (R) 25,137
Many electors suspected that something was amiss. Election officials worked late into the night counting the backup paper ballots. They declared a different result:
Kassis (D) 26,142
Scomilio (R) 25,137
The Republican candidate conceded, and the Republican Party stated that they would not demand a re-count.
In my opinion, it is fortunate that the election officials did not rely on the electronic total and insisted on performing a manual count of the backup ballots. The error in Kassis' vote was a failure to count 99.4% of his votes electronically. So it was a glaring error. (Maybe even a Soviet-scale miscalculation!) A more subtle error of perhaps 10% to 20% might not have attracted as much notice.
A spokesperson for Election Systems and Software stated, "The election was legal and fair."