Going back to Columbo (not to beat up on the show, because I do love it), I did a ‘Columbo rewatch’ thread a few years ago in which I posted what I thought was one of the weakest Columbo ‘gotcha’ moments (though not as outright dumb as the ‘guillotine’ gotcha), involving whether a potential witness was blind or not (if you click on the ‘replies’ at the bottom of that post you can also see a clip of the scene posted):