if they lie to themselves, can they be truthful to you?

No, silly:

A recently approved herbicide called Imprelis, widely used by landscapers because it was thought to be environmentally friendly, has emerged as the leading suspect in the deaths of thousands of Norway spruces, eastern white pines and other trees on lawns and golf courses across the country.

Manufactured by DuPont and conditionally approved for sale last October by the federal Environmental Protection Agency, Imprelis is used for killing broadleaf weeds like dandelion and clover and is sold to lawn care professionals only. Reports of dying trees started surfacing around Memorial Day, prompting an inquiry by DuPont scientists.

“We are investigating the reports of these unfavorable tree symptoms,” said Kate Childress, a spokeswoman for DuPont. “Until this investigation is complete, it’s difficult to say what variables contributed to the symptoms...”

Difficult for some, but not impossible for anyone who's used it apparently.

...“It’s been devastating,” said Matt Coats, service manager for Underwood Nursery in Adrian, Mich. “We’ve made 1,000 applications and had 350 complaints of dead trees, and it’s climbing. I’ve done nothing for the last three weeks but deal with angry customers.”

“We’re seeing some trees doing O.K., with just the tips getting brown, and others are completely dead and it looks like someone took a flamethrower to them,” he said.

So far, the herbicide seems to affect trees with shallow root systems, including willows, poplars and conifers, he said...

You know, just about everything.

...The chemical name of the product is aminocyclopyrachlor, one of a new class of herbicides that has been viewed as safer than earlier weed killers.

DuPont, landscapers and others had high hopes for the product. It has low toxicity to mammals, works at low concentrations and can kill weeds that other herbicides have trouble vanquishing, like ground ivy, henbit and wild violets. It works on the weeds’ roots as well as their leaves...

Ah yes, the horror of wild violets .

The wildness, can't have that. Yet nobody stopped to think about this horror . Literally, as of July 14, I can't easily find a single publication about it's mammalian toxicology, just it's effect on weeds and analytical quantitation.

Sanity would not suggest you promote a poison for widespread use around homes nobody's seriously studied before. Just given that structure and a drug metabolism course I took 30 years ago, I can vouch that chemical is at the very least a hepatotoxin. Much less what it's doing to your conifers.