If he ever calls anybody. I know plenty of people that never actually phone anybody on their smartphones, it’s just not that useful a feature for them. And they aren’t even paranoid types, if you’re paranoid (like the level of understandable paranoia a terrorist might have) you can use apps like skype to make “phone calls” that completely bypass your providers switchboard and therefore records. Same with texting, there’s lots of texting website out there for legitimate use that have other uses for those obfuscating their trail.
Shoot, even gaming-software support software allows you to record conversations. Individuals, of course. I know guys who pour through the logs each day. I always suspected they did.
A couple weeks ago, somebody confirmed to me, without being prompted, that they were doing it. It was already obvious to me by observing their actions. One of them, a persistent problem, had been discussed just a day or two before.