A different thought - is it necessarily goodbye safe harbor? The PLAN does not restrict anything. So the operational error must be corrected, (make up deferrals and match as required under the terms of the plan and the self-correction procedure) and then exclude them prospectively as an excluded class, assuming you can pass coverage testing. I'm no lawyer, but I'm assuming the terms of the employment contract can be modified with the agreement of all parties?
Looks like Jpod and I were replying at the same time...