With SIG USA specifically there's a long track record of making firearms that can only be described as problematic. For example, their attempt to adapt SG 55x to the American market - all versions had some issues, but especially so the ones chambered in 7.62x39.

The unusual thing here is that this is a problem in a product that managed to pass US DoD acceptance testing. But the drop safety issue was already known at the time, so one has to wonder just how much in soft bribes SIG had to spend to get it adopted regardless.