What if they were hovering, doing some regular thing in a gear up configuration (for whatever reason, I think this is mostly a test aircraft, isn't it?) and had an engine roll back? That would make you settle. Note, this is speculation.
@SASless: I don't think that's a taxiway. No markings. IF that pic is from the West Palm Beach facility, I don't think there are any taxiways there. (Memory foggy, been since the late 90's that I was there...)