I have heard of this indeed. The article is very interesting and is in complete contradiction to what HHDL says and yes the irony of it all.
I found this very cute picture of Ngari Rinpoche as well and some extra information:
Jetsun Pema, the Dalai Lama's sister recalls her little brother in Tibet My Story, London: Element , 1998 pp.41-2, "At the same time, another reincarnation was living in our house: my youngest brother, Tenzin Choegal, a rinpoche or spiritual master to whom we also paid great respect. He, however, shared our everday life and was sometimes very mischievous. At meal times, he did not think twice about getting down from his chair and joining us to be naughty, much to his tutor's distress. ... Everyone let him do exactly what he wanted, because of his position as a rinpoche."