He was detained for several hours & missed his flight but they eventually reluctantly decided that the sniffer machine was giving a false positive.
Security and technology has improved much since then. Those early devices may have something that was off-gassing something that triggered the detection.
I was detained years ago after gunshot residue was detected on my clothes. I had been out shooting with my brother a couple of days prior. I was given a thorough pat down and cleared. My carry on was searched and also cleared. It only took a couple of extra minutes.
The strangest I have ever had happen was when I was leaving Norway at Oslo Airport. I was already past security and in the passenger waiting area. Some security officer was walking around, came over to me and asked me to go with him. I gave all my carry on stuff to my wife to keep safe. He never batted an eye. They were interested in me, not my carry on. Strange.
I was taken to another room, my passport was taken and went to another room, and I was told strip to my underwear. My clothes were methodically searched and felt over almost every inch. The entire search took about 20 minutes. Me, alone in a room, with two security people, in a foreign country, with no passport. I was significantly concerned. The agents would not answer any questions.
Eventually I was given back my clothes, told to dress, my passport handed back, and told it was OK to leave the room. To this day I have no idea what triggered the search. I can only surmise that I must have looked like someone in which security was interested, or my name matched someone of significant interest.
Subsequent trips to Norway (two of them) I have been subject to additional scrutiny but nothing like on that first trip.