This likely refers to the [nearly] instantaneous propagation of the radio waves used to send the audio signals to the radio.
In the elevator world, a trip takes a non-negligible amount of time, in the order of seconds. The trip also involves a distinctive experience, e.g. the acceleration and the deceleration, the shaking of the cabin, as well as the sounds, involving the rattling of the cabin itself, the cables, and sound of the motor used to move it.
I'm guessing all of those are important for the elevator inspectors, as those can tell them about the condition the elevator is in, how well it's performing, and whether it is in need of service - e.g. creaking and screeching may tell them something needs to be lubricated, and rattling may point to loose parts.
On the other hand, the radio waves propagate, for the purposes of consumer radio, almost instantaneously, to the point where it takes longer for the audio waves from the radio to reach the listener a few meters away than it takes for the radio waves to reach a radio receiver a few kilometers away.
In this regard the "trip" the radio waves take is (almost) instantaneous and the end product - the sound - bears (almost) no trace of it, a complete opposite to what the elevator inspectors are used to.
Perhaps, in that case, they might find solace in the fact that there's a delay introduced by the circuitry required to route the audio signal and produce the radio wave. Although this delay is negligible for end-users, it might evoke some familiarity for the inspectors.