I have been used as a "scent article" in more than one training drill with my skill sets in tracking and evasion. Cadaver dogs have hit on me when I have been covered in leaves and forrest debris. They even hit on me when my hiding place was misted in fox urine to throw them off. And since I have been doing this for over a tad over 50 years, including managing air and ground scent dogs on SAR missions, I am most respectfully going to disagree with you. Oddly enough, I had an explosives dog alert on my travel bag when I was in Philly International. I was detained until the bag was swabbed and found clean. I have never had anything even close to explosives, gunpowder etc anywhere near the bag in question.
(Bowing to your lengthy years of experience with SAR dogs). Sometimes the trouble with understanding an alert comes from the fact that the dog cannot tell us exactly WHAT it is they are smelling. Or alerting to. I will not go into my experience with dogs on this matter, however I do know that we, as humans often times minimize or dismiss information when we don't understand it.
You do not know if the dogs were alerting to YOU or to something on those leaves or something on that ground. There may have very well been something on that forest ground that triggered an alert. We will never know because we cannot ask the dogs and you are
assuming that they were hitting on you.
The fact that they hit on you even when you were misted with fox urine tells me that the dogs smelled something and went with their training.
Can dogs be wrong? Of course. It would be foolish to sit here and say dogs cannot be wrong.
As far as your travel bag is concerned? You just never know. You easily could have picked up some sort of trace material somewhere you don't even know about. In a hotel, from a hotel floor, carpet, anything. Swabs are designed with a threshold that doesn't remotely consider what a dog's scent threshold is. The swab comes back and says your bag is 'clean' because of the calibration thresholds established to determine these things. We already know that dogs can smell minute trace, most likely far lower than lab result thresholds.
The fact is that our items come in contact with just countless other objects all day long especially when we travel and we don't pay attention to it. That's the truth and the proof is with bedbugs or virus, a hundred other contagion type transfer issues.
If you ever wonder if that is true, take some Dawn dish soap and put a drop of it on the bottom of your luggage while you are in a hotel room. Pick up and set down that luggage, forget about the dish soap. Before you leave the room, take a black light and shine it and you will be astonished at how that tiny drop of dish soap has transferred to a variety of surfaces in the room.