(TP, Bball, was typing (very slowly) while you posted.)
This would not surprise me, nor would it surprise me that the relationship hasn't soured, but rather was never great in the first place...more of a mutual tolerance.
Rondo is not the most patient, understanding guy in the world, and Ray is reported to have OCD. That is not a good match.
Rondo's mercurial, inconsistent, flamboyant nature wouldn't be comfortable for Ray. OCD people like routines and consistency. The are bound to them.
Also, Ray's OCD, as with most people with OCD can exhibit behaviors that are both annoying and alienating. And, Rondo seems easily annoyed and alienated.