hi mate glad your 715's are ok, hopefully will stay that way too.
went to my local gun shop today, (lol start calling it my second home soon) asked them if they had any 715's come back yet, they said yes just 1 out of 13 so far, it had a broken trigger but howard also said what you did, hes pretty sure that the owner tried firing the gun with the safety on and forced it and broke the trigger mech..

We will have to keep a close eye on these, but as 'anything' in life, some will break and some will not.

happy shooting mate.