Full Idea
Though special relativity does not determine a preferred frame of reference, it does not rule out the possibility of a frame being determined from outside the theory. Perhaps we should prefer a frame where background radiation is equal in all directions.
Gist of Idea
Special relativity won't determine a preferred frame, but we can pick one externally
Source
J.J.C. Smart (The Tenseless Theory of Time [2008], 3)
Book Reference
'Contemporary Debates in Metaphysics', ed/tr. Sider/Hawthorne/Zimmerman [Blackwell 2008], p.233
A Reaction
Of course this is a mere philosopher offering the escape clause, and not some Nobel-winning physicist, but I start from the assumption that this idea is plausible, and I am unmoved by the contempt for presentism among relativity geeks.