While I've been lucky to have never had any firearms training that I considered remotely unsafe, I did take a rock climbing class once and it was so bad that me and my partner would only belay for each other and before the end of the class, we told the instructor that we had seen enough and left on our own. It's really not easy when you are new because the dangerous aspects aren't as obvious to you. In the rock climbing class, it was only my second time climbing and I didn't really know any better, but my partner had a wealth of experience and she pointed a number of things out to me as the day progressed. In hindsight, I can't believe we stuck around as long as we did. Sadly, sometimes the cost of a class makes you stay longer than you should.