Thanks for the flowers, but Kyle is certainly several levels above me 
Just as @prolog, I’m curious how you can be so sure that this is what happened. The reason why we have a hard time believing this, is that this would be a really high level attack. We know these are possible and happen. Just not that we regularly talk to somebody who was a victim.
Just today I learned that Andy Müller-Maguhn, a German ChaosComputerClub member, is certain he’s been compromised (spy device inside his cryto phone) by the CIA 
for helping Julian Assange.
Related video in 
If you need advice, ask this guy…
To reiterate, if data (that is not on your screen) is leaving your device, then there is software on the device that makes it leave. Either intentional (you copy it), unintentional (cloud backup, anti-virus), or malicious. This is already true if you HAVE a radio. If you have no radio, there has to be malicious software plus a receiver in close proximity.
Thinking about the low data rates that side channel attacks provide, I just thought I’d rather try to place a sender in the docking station, the power plug or anything else you attach to the device that looks unsuspicious.
Still, can you be 100% sure the data was stolen from THIS device and not from a different one? How?