GB is most likely correct, but it could also be as simple as having some sticky goo in the trigger housing. If it is working properly, the safety cams the sear bar off the trigger shoe when applied. If the trigger is pulled with the safety applied, and there is goo in there, it can stay stuck to the rear in firing position. Then the only thing holding the sear bar is the safety. So when it is released, the gun fires. It is important to never use anything that can gum up one of those triggers, like WD-40. Some dry lube on the sear engagement surfaces is fine, but nothing anywhere else. BTW, the new redesigned Remington trigger addresses this design. The safety positively cams the trigger into engagement with the sear when it is released. I think it's going to be a good design and am looking forward to having them in production.