If they're taxable income, it would be based on the cost of the passes, and not depend on how they're used or not.
It's still a question on if they're really taxable or not. If you assume they are, RCID would need to report that value to employees. So, it's not just an accusation that RCID employees were incorrectly reporting their taxes, it's an accusation that RCID accounting, the prior board, and anyone else who signed off on the RCID finances all did it wrong too.
I don't know the rules for when something becomes material and needs to be reported as part of your income. Nobody thinks if your employer gives you two movie tickets you need to include that in your taxable income. However, if they give you a car, that's probably taxable. There is definitely an IRS publication that would give you the details, or at least guidance on how to make the decision.
If we have a tax accountant reading, they'll probably know which publication to reference.