To be fair, nothing in your second link explicitly says that testing was done by PCI SIG. It could have come from the 3rd party that provided the initial reports of failing connectors to PCI SIG, and PCI SIG is just forwarding those results along with their email. In fact, it looks like those test results come from Nvidia (part of the same package as the page that spongiemaster posted above)Check out the second link. Read through the whole thing.
See here (starting at around 7:00):