The safety failure reported by some owners isn't the actual knife lock failing, it's the sliding tip lock that you can see in the third picture of this drop. It slides back and forth and locks the knife blade in the handle when not in use. If that breaks for whatever reason, you can contact Kershaw and they'll send you a new one.
The frame lock that locks the knife blade open is very unlikely to fail in any normal use.
The frame lock that locks the knife blade open is very unlikely to fail in any normal use.