Snorkeling is inherently dangerous. Color me skeptical here...
Point taken and I'm not averse to risk for me or my kids. But we're not talking about an uncontrollable risk inherent in the activity (eg. nature, waves, creatures big and small). Here we're talking about a risk (however small) from inferior gear with a potential design flaw. That risk is easily avoided (and peace of mind easily attained) by spending a few extra bucks on traditional snorkeling gear.
This is just impossible to wash from the mind. My kids are crazy-strong swimmers and I would be watching them every second worrying about the risks from a POS $10 knockoff mask from China.
Edit: And when it's my wife that says: "Return," it's not a battle I'm willing to fight. Not worth it.