I have the same thing happen each yr with aPaph in the appletonianum alliance. The bud/stem of course is very soft when first trying to imerge from the crown. In my case the bud gets stuck in the crown BUT the stem continues to elongate, slips past the bud and finally it all comes out at once. The result is a "S" curve in the stem. The stem begins to relax and straighten as it continues to elongate, hence an up-side-down flower bud. By the time the bud is ready to open, bingo! a normal flower with a slight kink in the stem. My plant has a 2nd bud coming up, I'll try to get a pic