It was attached with rivets, I believe, and sloppily done. The aluminum ordinarily used would almost certainly not have pierced Concorde's tire. A certified part would have performed to an expectation. The pirated Titanium was not suitable.
That leaves everyone involved in its attachment liable for a portion of responsibility in the crash. Regardless when, or even IF, it pierced the tire.
Wrong means wrong, and carelessness and shortcuts never ever pay.