You hear that a lot, but I don't think it's true. If you follow the rules of safety assiduously and do not violate them, you shouldn't have a problem.We shooters can be separated into two groups: those who have had NDs, and those who will.
It just isn't that hard to clear a semi-auto. Drop the mag. Lock the slide back. Check that there's daylight all the way through. Work the slide a couple of times. Look and check.
Skip any of those steps at your own peril.