I understand that. The point is there are very few (if any) single security layers, physical or digital, that can claim otherwise, i.e. that can't be "fooled 10

I understand that. The point is there are very few (if any) single security layers, physical or digital, that can claim otherwise, i.e. that can't be "fooled 100% in a well defined flow". People here should be aware of that more than most.