First, to get this out of the way, we have had a lot of new folks coming in here, referencing Tac Response and bashing fcg's, so prepare yourself.
I would like details on this if possible. Where exactly did the disconnector break? Up towards the hook or more toward the bottom? Did this guy try installing the pins provided to properly set this up in his Arsenal? Was he experiencing trigger slap? He should have been if it was bottoming out on the rivet. Did the rivet display any deformation or marring?
Also, I believe all Geiselle products are MIM are they not? There's not really anything wrong with the process for components like this as long as they are properly heat treated after. You don't have to have the superior grain structure of forged or even machined billet for these parts to last. For the record, these ALG fcg's are crazy hard and durable. I had some issues modifying one using a mill. My endmills barely took a bite out of it. They aren't just hard either, they were that kind of pain in the ass to mill steel that doesn't even want to chip off. IF one did break, I would be really interested in seeing photos. It shouldn't just snap. It should deform a bit first because they are well made.