Didn't it ever occur to to the captain that VHF frequencies are not encrypted and that anyone with a scanner can listen? The reason she gave him a phone number is so he could get the information he needed and then he still demanded the info over the frequency.
Even telling the pilot that there is a "safety of flight issue" or something like that would have probably been much better than saying nothing at all. There could be restrictions on cell phone use in the cockpit with which the pilots would have to comply.
I'm honestly a little shocked that there are not procedures in place that inform ATC, pilots, and emergency personnel about terrorist activity in a manner that keeps them all on the same page. Being in the pilot's seat, I would be equally as shocked at the situation as that guy was. I don't blame the controller for not being able to relay information to the pilot, but by now you'd think the FAA would have developed some procedures for this type of incident.