A worrying issue but at least you were safe and no accidents happened. I had one in .416 Rigby as well. You have sent off the rifle to CZ so this is a bit late. The #1 best thing you can do to a CZ is have the factory trigger re-built by someone who knows what they are doing. You can retain the set feature if you like, but don't have to replace the entire assembly. It is the best $50 you can spend on a CZ and isn't anything more than you would do with most factory rifles these days.