Not experienced this myself, but it's one reason I teach students to never trust any mechanical safety mechanism without verifying it, and never point the muzzle at anything you would not destroy (particularly including other humans). I take muzzle awareness so seriously that I have asked students to leave when they ignore this simple safety rule.
All safety mechanisms can fail.
The rifle may have been assembled incorrectly, a part damaged or defective. S&W will make it right.