I suppose a "refusal" could be inferred by the lack of their acceptance on the initial buyout offer and their (apparent) rebuttal of a $2.5bil valuation.
For instance, if I offered you a million dollars cash for your house and you came back to me with an appraisal saying it was valued at $20mil... I think it would be clear (or at least strongly insinuated) that you refused my offer of a million dollars.
Thinking that's kinda what happened here? Seems like Elon didn't take to their method of countering and called the whole thing off.
Just my $0.02 and I'm not privy to all the inside-details. Could've gone down entirely different than any of us know.
Plus, it seems like there's a LOT of infighting among the co-founders and previous team. Will be curious to see if more information emerges.