The problem is that firing Rafa could lead to the exodus of the Spanish talent away from Anfield. Without Alonso, Torres, Reina and Arbeloa (all Spaniards) and Mascherano (Spanish speaker), Liverpool is no better than the other UEFA Cup candidates.
Sure, selling those players would raise some cash for other transfers in, but that level of instability is dangerous. Gerrard and Carragher are also getting towards the back ends of their respective primes and they may want to go elsewhere for the end of their careers if Liverpool is in crisis.
Hicks should have never opened his mouth and let Rafa hang himself. This poor run of form coupled with the likely exit to Inter in the CL would have been enough for most of the Liverpool supporters to give someone else a shot.
If I were Hicks, I would have sealed up Mascherano, never publicly discussed Rafa or his future, got the refi and stadium deal locked up and waited to see how Rafa performed during the second half of the season. I would then fire Rafa and hire Jose.