My point is in relation to the legal and liability-related elements of the previous posts not the validity of proofing or old guns. If you want to question the validity of proofing barrels in today's day and age that's your choice. No amount of proofing replaces or protects from stupidity or stupid mistakes, as noted
Personally, I choose to place more trust in a proofed barrel, a standard process employed for real arms today and for hundreds of years prior, and rely on myself to avoid stupid mistakes as opposed to pretending that barrel proofing is worthless because it doesn't cover stupidity.
If I am injured due to my stupidity or carelessness, so be it. But pretending that products of unknown origin are of a particular quality level or eliminating even a particle of risk to my life to save $900, are not worth it to me.