Poorly designed and/or executed liner locks are awkward and can become disengaged allowing the knife to unlock. I don't have an example of the knife in question so I'm speaking in generalities. Properly done a liner locker should be fast and convenient for one hand operation with a daily carry knife for normal cutting chores. I wouldn't trust one for heavy duty use.

Every normal man must be tempted, at times, to spit on his hands, hoist the black flag, and begin slitting throats.