I think it's very sad to see such results and have to admit that I kind of hope something horribly wrong has happened and it's all just a bad dream. I've been doing some research, asking around a bit and Five Pawns have ensured both retailers and end customers that their liquids are diacetyl free. Now, as Dr. Farsalinos also mentioned in his appearance on Click, Bang!, the e-liquid manufacturers might not be the only ones responsible for this, as DA and AP comes from the flavour concentrates used. So Five Pawns might have been told by whoever they buy their concentrates from that they don't contain these chemicals. However, as we've now seen, e-liquid manufacturers should not trust this, and in my opinion they are still responsible for testing the finished product. It's the same thing in my own line of work (I work for an ISP), we cannot blame the manufacturer of our CPEs when they release a new software that breaks something, it's our responsibility to test it thoroughly before it's rolled out to customers. I'm probably not the only one impatiently waiting to hear what Five Pawns has to say about this.
Again, I think it's a good thing that resellers are doing these tests and publishing the results. This puts pressure on the manufacturers who will now have to start taking this seriously or they will probably be out of business even before regulations are being implemented.