I didn't read the article yet, just got home from work.........but I would guess they are referring to people using heavy amounts of weight. Huge bodybuilders using really heavy weights (or anyone for that matter using heavy weights) could do some damage. Especially those bodybuilders who are on steroids and other anabolic drugs who think they can handle more weight than their muscles, ligaments and tendons can really cope with.
Sometimes I have felt some "strange" sensations doing them, but that was because I used heavy weight and had a hard time getting the weights back up after the stretch part of the exercise.
I still do them, but with weight I can control and still feel a burn at 8-12 reps. You can also use cables if makes it easier to balance than with dumbbells.
I'm heading off to the gym in a few minutes to train chest