Pleurotus on Piñon

In the fall of 2005 our dead trees produced Oyster mushrooms (Pleurotus sp.). I grew Pleurotus commercially for more than ten years, and in that time I heard about a lot of different hosts/habitats, but I never heard of it fruiting on piñon and would have been hard pressed to believe it if I hadn't seen it with my own eyes. They fruited in 2005 and 2006, and then disappeared.