Given that school budgets are absolutely gutted with mass layoffs this year and next, and the miscalculation looks like 2/3 of the budget shortfall, hiding such a basic and impactful error requires a much better explanation than I see in that article. It looks like it was done to stifle debate about budget allocations, which would be necessary in the circumstances.
The education system seems one of the only places where vastly improving technology over the past 30 years has not translated to cost savings or improved outcomes.
Gains in efficiency due to technology improvement, as far as I know, are always attributable to fewer people being able to do more / produce more. There are some things that will never have gains in efficiency. Technology will not reduce the number of players on a football field from 11 to 10.