A search online suggests the Dallas County machine in question might be an ES&S iVotronic, for which Texas requires no paper record.
Verifiedvoting.org reports that the iVotronic has security concerns, and last week in North Carolina iVotronic machines had touchscreen calibration errors:
Some voters in Guilford County have found errors when reviewing their
ballots before submitting them — namely that they meant to vote for a
candidate of one party, but the machine marked their ballot for the
Elections Director Charlie Collicut said the problem comes from the
election machines’ touch screens. As some voters touched the screen,
it would select the name above or below the candidate they actually
“It’s a machine that we have to calibrate — that a human being has to
calibrate,” Collicut said, pointing out that the process isn’t
He instructed voters to try pressing a millimeter above or below the candidate name until the correct box is checked...
- NC Election Directors Urge Voters To Check Their Ballots After Touchscreen Mistakes By JESSA O'CONNOR • OCT 24, 2018
Unlike Texas, North Carolina requires by law that iVotronics machines output a paper receipt that shows the voter who they voted for.
Ten years ago (10/27/08) the Brennan Center for Justice sent a complaint letter to 16 Secretaries of State, (in states using iVotronics machines), that warned them of poorly calibrated touchscreens and "vote flipping".
So the answer depends on circumstances:
If an iVotronic machine hasn't been hacked or tampered with, and doesn't have other unknown backdoors or major bugs, then once its touchscreen has been calibrated correctly, it should probably be OK.
For those interested in further analysis of the ES&S iVotronics shortcomings, see: