Most likely it's just hyperventilation caused by walking around sniffing the air looking for the source of the smell. Although I wouldn't doubt the smell was toxic.
I've never seen hyperventilation caused by 'sniffing'. I wouldn't go so far as to say it's impossible, but you'd have to be sniffing far more aggressively than I've ever seen someone sniff before...
The article says "smell", not "smoke", but I don't think inhaling it was a good idea in any event.