In a similar vogue though its unlikely that Ferrari would have emptied the tanks for Massa or Kimi just to prove a point.
Yes it is very difficult to judge any speed / or lack of / in testing as they all have different programmes but at some point during that programme one would think they would empty the tanks to simulate the balance of the car on low fuel - that includes Mclaren and Ferrari and all the others.
Not pointed at you Rpstewart, but I love how (inc ITV-F1 commentators) love to point out that when Ferrari is quick its cause they are running empty and when anyone else is, its because their car has fundamental speed. Hilarious based on the number of wins Ferrari have posted over the last few years