Actually, very much yes. The device to be tracked needs to be exploited somehow in order to run the code to advertise its existence via BLE.
FTA's "Architecture of nRootTag":
> (1) The Trojan code runs on the computer to be tracked.
FTA's "Architecture of nRootTag":
> (1) The Trojan code runs on the computer to be tracked.
But there probably aren't many situations where someone has a network-enabled device turned on, disconnected from the network, but in range of at least one iPhone that has a network connection. Perhaps on a plane?