Agreed with the last two statements. I do not like the "fine" method because I do not know the related case law. I am not saying it is certainly illegal but it is legally problematic. I do know the (federal) case law on making deductions from the above minimum wage portion of the paycheck. Only stupid employers take something that should be legally simple and turn it into something legally uncertain.
Call up state DOL. Or roll the dice and take it small claims court. You can take exactly the same set of facts to three different small claims court judges and get three different answers. It is always easier to make the decision very obvious for judge or ALJ. Labor law has been around for a long time and most issues were well decided a long time ago. It might be a court decision instead of a regulation or law, but the chance you are the very first person with this (or any other) issue is small.
A pioneer is someone who ends up face down in the dirt with a bunch of arrows in their back.

