That's also not what's said.

There's plenty of articles debunking this. Other articles make it more clear, that the dogs are responding to their handlers intuitions, in order to make them happy and get treats.

That there "was once drugs in the area in the past some time" or else where at the rave/nightclub/house party, so residual odor claims can be made." isn't the same as confirming that's what the dog was picking up on.

You're falling for cop-logic.

Here's more studies on it. It's widely debunked.

https://www.criminallegalnews.org/news/2018/feb/16/research-needed-do-drug-dogs-respond-drugs-or-handler/

https://advancestudy.org/how-accurate-are-drug-dogs/

https://scienceblog.com/explosive-and-drug-sniffing-dog-performance-is-affected-by-their-handlers-beliefs/

I think the biggest truth that goes unsaid is that cops use sniffer dogs the same way they use lie detectors - as a means of pressuring suspects.

They're good boys who have been corrupted by opportunistic jerks.