Sure, it's possible they didn't know; just as it's possible that the bolt may not have been lower quality (which is why I said 'if'.)
The point of my post wasn't to detail out every reason I may have had to take my business elsewhere, it was that I should have trusted my instinct in first place and that I don't personally find every situation crying out for me to point my finger at someone else. My apologies if it came across as anything else.