That's the fucker about these laws; in a lot of constitutions (note that the UK does not have a constitution so I'm not sure how it works over there), you have the right to not provide evidence that may lead to your conviction. But rules like this go counter to those.
Worth calling their bluff, I reckon.
You're gonna leave your family, lose your job, have to explain to everybody you know that you were in jail for a while. For a good story?
Don't live in fear, that is not worth it.
For millions of people it would be a disaster that you don't just smile your way out of with some optimism and a laughingly good story. It's not just about "don't live in fear", Instead it's often a harshly practical matter of "oh shit, i'm going to jail for months, the bank will foreclose on my home, my job will fire me and my kids are fucked".... You might be okay with that, but it's no fucking joke for many, no matter how lightly they try to take the burden.
Yeah, but that involves a charge, and you get a lawyer.
I would have refused to answer anything without first consulting a lawyer; I won't take legal advice from the investigating policeman. "You say I have to answer? Fine, I'll answer if my lawyer confirms that." What can go wrong? The worst that can happen is that they charge you (with something?) for refusing to answer. Voila: legal advice.
I guess Craig's devices didn't have much of interest on them; he travels a lot, and has been mauled by the law more than once. So he can give up the passwords with confidence. And presumably they already knew what meetings he'd attended, with whom.