I am still a neophyte to orchids and pahs. I have paph that started to open 2-3 weeks ago. The upper petal on the flower has not become fully open & is still in a horizontal position while I have a couple other paphs that have bloomed after the one in question and are fully open. Any reason this one is taking its time to show all its glory?? Otherwise all is well with my plants. I have not killed any yet :-)
Some Paph species have a tendency to hold the dorsal sepal forward (I think this is what your talking about when you say the upper petal), although generally not horizontal. Is there a name tag on the plant in question?
I was careful when staking the spike not to impinge anything. I think perhaps its just slow. I have another pah that it took a good 3-4 weeks for it to open fully but I thought that was due to temp stress it suffered in shipment. I guess it will open fully in its own time, or not.