Their spoken words have very little value. They're willing to directly lie about all aspects of this and have demonstrated that repeatedly.

They initially - and to varying degrees still - claim they did not and do not spy on Americans.

I don't think you have to worry about tells. Given what we already know they did, assume they've done much worse. It's a very safe bet. Assume they're monitoring every single thing they can get their hands on when it comes to international leaders.