They're being hyperbolic. There are illegal grow operations in southern Oregon, but not on the scale he's implying, and there absolutely is enforcement. The illegal grow ops also don't use any form of large scale irrigation that would impact other water users substantially. They grow in natural areas with an attempt to conceal the patch of plants from airborne surveys. Reading that comment you'd think southern Oregon was like Sinaloa Mexico where mass scale plantations operate openly. That's a totally incorrect portrayal.
I have a home on 10+ acres of forested land in Josephine county about 20 miles north of this farm. The owner is not being hyperbolic about illegal grow operations.
Just a quick perusal of google satellite imagery shows quite a few operations in the area around seven seeds and the Applegate valley (look for long runs of hoop structures).
It is true that the number of operating illegal grows has recently dropped dramatically since legalization in Oregon (mostly because it is hard to make enough money versus large legal growers).
Since this got downvotes quick, I'll just elaborate that over the years I've had a pretty diverse friend group, and while it's not my world, I know several people who worked seasonally on these grow ops doing trimming. One of them got caught in a DEA raid. I'm not just blowing empty wind here, as well as my other claims can be trivially verified with a little googling (particularly that there is enforcement).