The point is that you did not need to know about the specific broadhead.

You know what the legal cutting diameter is, without looking up a specific broadhead.

I don' t think it is reasonable to expect the GC to make a ruling on every model/make of broadhead out there.

Brand x might have only .5 of an inch cutting diameter, so the PGC would have to have a release stating that this is illegal?

It is our responsibility to read the regs and to ensure that we are using legal equipment.