When glass is tempered the pane/panel surfaces strength is significantly increased for both loads and impacts.
Additionally, when glass is tempered its pane/panel edges are not able to withstand loads or impacts laterally to its surface face (Side Impacts). Most tempered glass for furniture use has beveled/ground edges to reduce the chances of direct side impacts.
Having worked with a glass/window manufacturer, there are a lot of anecdotal incidents regarding tempered glass failures. Most failures in our experience have resulted from damage after production - that is during handling, packing, shipping, at retail, during installation, and post-install. Permanent damage to tempered glass may occur and may not even be visible. Of course, there are bad batches of tempered glass, but as one poster has pointed out already, this company has not had any formal BBB complaints and this (so far) seems to be a singularity instead of a trend.
Looking at the state of the situation makes it clear that a catastrophic failure occurred, and there is no way of telling why at this point. Having seen this story at a number of internet "news" sites already, with most voices vilifying the manufacturer, does not seem to be the rational line of thinking in my opinion. There are countless ways that this failure could have occurred, some of which are the responsibility of the manufacturer, and some of which are not.
Ultimately, one would hope that the manufacturer has taken into consideration a % of product failure into their product planning and will step up and provide good customer service regardless of the fault - thats a sure way to improve a bad situation as there is no way that a consumer can prove that the glass was damaged from manufacturing or shipping now that its destroyed and there is no way for the manufacturer to prove that the shipper, or customer caused the damage. One can only hope that the situation can be resolved without the need for such right/wrong, good/bad polarization unless additional facts come to light that would help illustrate such a situation (such as information coming to light that illustrated a trend of this occurrence from this manufacturer).
From an emotional side: I emphasize with your loss and the mess you have, and the damage that occurred from that. Thats not the way to start the week.
I hope everything turns out OK in the end.