I'm going to have to back up the truck for a minute...
I have never heard of these research reports showing diethylene glycol that were posted by the National Institute of Health.
Do you have a link to any of these?
We all know about the FDA finding approximately 1% diethylene glycol in one of the 19 samples they tested.
But I have never heard of anyone ever finding any diethylene glycol in any other juice either before or since then.
I suspect that they tested a few more samples than they published results for. In spectrograph analysis, you can find traces of many chemical signatures. I'm sure there was a contaminated sample in the bunch where DEG got into a batch of PG during manufacture. Just like peanut traces get into foods in factories that make other foods, I can see where strict QC could allow DEG to contaminate PG if someone wasn't careful. Our water isn't 100% H2O, either.
The antifreeze scare was also elevated by the fact that DEG was replaced by PG because animals like the sweet taste of both. Dogs would lick up remnants of DEG based antifreeze drained from a radiator and die from ingestion. Once PG replaced DEG in antifreeze, dogs could lick up antifreeze and not be adversely affected. PG is in many of our foods, also. Check out the ingredients of sno-cone juice at the store, your salad dressings, your make-up, and your toothpaste tube. But, that gives people the ammunition to say that ecigs contain a component of antifreeze.