Ya, thinking that too. The hose on the FPR is essentially just sleeve on, so I can see where maybe some years of rubber-corrosion on the hose and some road vibration could work it loose. It is right above the location you are describing anyways.
Here's to hoping it's a case of, "oh this is all it is".
Gary Noonan
'01 S/C VX / '18 Forester XT