I'm not familiar with the acronym "DRE," and don't grasp what you mean by "not a technology problem."
My high opinion of ink/paper ballots may be misplaced. I admit and expect errors in the optical scan process, but when the contest is close, there is less interpretation of an ink/paper indication than of a hole-punch indication. That is, the audit is more reliable.
As for gross, outright fraud (adding a stack of punched ballots, or a stack of marked ballots, "voted" by one individual), all systems have weak points that require guarding.