Good eye. I figured that he would have screwed it up in some way before it failed like that. It looks like the inside of the retainer plate is a little chewed up. I wonder if he tried to smash the spring guide in there backwards a time or two before reassembly. "Make it out of aluminum, because metal!" people seem to be the same that don't trust PMags "Because plastic!". In his hands, it doesn't matter if it was made out of an alloy of adamantium and mithril, because he'd screw it up anyways.
I don't get the folks who are being overly critical of Sig for this. Unreported in the field and extremely difficult to replicate in the lab. I do think that they could have had better execution on the upgrade program with regards to the training of their customer service reps and their estimated timelines.
I'm inclined to believe that the UK Metropolitan police and others who have adopted this platform have done a significant amount of testing on it. I don't think that if there were serious flaws with the weapons system that Sig could get them to buy it. Everyone keeps on saying "QC", when they don't realize that it's not a QC issue. The accuracy issues were a QC problem. This is a redesign. Even Glock and FN, among other very reputable manufacturers, has had recalls and upgrades to otherwise fantastically reliable weapons.