Contact highs are extremely real. I first noticed them because my ex-wife didn't know when I would take drugs and I can't even count the number of times she would display aspects of my high (even to the point of seeing the carpet morphing). I used to run experiments, I had some friends who tripped sometimes, and I'd take psychedelics when we'd, say, go on a day of bike riding or hiking. One time in particular, my friend and I were watching some clouds as we rested for a few minutes, and I was on DOC, somewhat like LSD, watching the clouds bend and morph. My friend was staring too, and suddenly said "dude, I feel like someone gave me acid. The clouds are morphing, WTF?" A good friend of mine almost never actually takes drugs with me and our other friends but it's usually at his house and he feels like he comes along with us on our trips (his own words).
Not sure how, but something is going on there.
(not trying to compare your friends kid to a dog but oh well, what can you do :D)