As someone else pointed out, look at what Cillian allegedly said:
"I can't count on that at the moment, I'm afraid," he reported.
Uh, what? "I can't COUNT on that at the moment, I'm afraid?" That's an odd sentence, at best -- translated literally, it suggests that Cillian was looking forward to this "job," but it doesn't look as if it's coming through, or they're hiring him at the last moment (a scary proposition, if he has other work and can't make the schedule.) The only way that sentence makes sense is if he is/was expecting to be in it, there's been talk, but he hasn't signed any contract yet. (And without a contract, nothing's a done deal.)
I think he was misinterpreted/mis-heard. I think he said:
"I can't COMMENT on that at the moment, I'm afraid."
Makes much more sense, and a "no comment" response isn't a "no." It's a "I can't overtly say 'yes,' or the studio will kill me."
-- Admiral Nelson