I don't have a problem with OC.... It seems more trouble than it's worth IMHO. I get paid to OC at work to do so for free seems like a problem waiting to happen.....if it is legal in your area have at it vive la difference
How this equates to him being able to determine that the internals have not been illegally tampered with by looking in the breech, I have no idea...
It's all about reasonableness. It is reasonable to assume that if the selector switch has no auto setting that it is semi-auto.