I was just reading something on bud blast and it talked about the effects of ethylene. Ethylene is a plant regulatory hormone, that often triggers flower, petal and leaf drop. (I'm not sure about abnormal formation of flowers.)
Fruit is a common source of ethylene - apples are one of the worst. I helped a friend run an apple stand in Vermont the fall after I got out of college. At the end of a long Saturday, we moved all of the mums that were for sale inside the little building (that had maybe 50 bushels of apples) and locked up for the night. The next morning every mum had dropped every petal! That was my ethylene lesson.
I don't know how it effects flower formation, or even orchids, but it might be worth considering. Another big source of ethylene is incomplete combustion. That can be from furnaces, cigarette smoke (don't smoke - it's bad for your orchid's health) and ...fireplaces!
Just a thought.