I have never heard of that before...
I think overdoing
any activity can be stressful, but I don't necessarily think it'll make a dog reactive or aggressive.
I've read this article at least twice, and my personal opinion is that the dog in question should probably not go visiting a friend after having played for a long time... she should be allowed to go home and conk out on her pillow.
I think the "overstimulation" is caused by the visit, not by playing hard/fetching itself.
I know that my own dogs prefer to chill out in our house, on their own beds/blankets, when they're tired... just like people (and especially small children) get cranky when they're "overtired" I would think the same thing might happen w/dogs.