&gt; So just to be clear: He said he used drugs, a gate agent smelled drugs, the cops smelled drugs, and you just want to argue that if a dog also smelled drugs that that dog is unreliable even though the arrested party says the dog was correct..?<p>There&#x27;s nothing strange about this.  On one the features of a drug sniffing dog is that it is supposed to be able to distinguish between a lingering odor, a passing odor, the presence of residue, and the presence of actual material - in a way that a human can&#x27;t.