It is surprising to me that so much debate is going on over this.  JM got caught talking off camera/off the record and saying something that probably has truth to it but also something that a professional journalist should not have been saying, even off the record.
"It will happen because he's told them he wants out, and no one believes me but that's the truth," MacMullan said. "And I don't see how you get 80 cents on the dollar for him. Tell me where."
I went back and looked at the exact quote again.  She does not say "demands a trade", but does say he wants out and has told this to the Celtics.  She has her reasons to believe this while the Celtics and Rondo have every reason to deny it.
The debate will rage on I guess even if Rondo is traded.  That still won't prove what he told or didn't tell the Celtics.