If it was an honest mistake they can explain themselves, but when the don’t even bother to report it then what else should anyone think? Not reporting tool breakages is itself a cause for problems around here and lends credence to the “someone knew they were doing something they shouldn’t”
We already allow committees to charge commercial users differently, and they do in one way or another.
Metal we don’t have much that will wear from that kind of use, but ensure that commercial users bring their own consumables for torch heads and pay for the associated costs of things like MIG and powder.
Laser has job time limits, machine those with commercial work tend to bring their own end mills and the like.
There are very few things where “drawing the short straw” in tool wear results in a charge. The cold cut saw is the only one I am aware of where this is the case, and even then it’s pretty rare that the previous users cause the damage that causes a blade break on your use, as it’s generally broken when the work piece isn’t clamped properly as taught in the training.