This kind of evidence implies that electromagnetic systems are involved either for propulsion or navigation.

In any case, if such means put out strong electromagnetic fields that can couple into conducting nerves, that can cause burns and nerve damage. For example, if you stood long enough in front of a military jet's antenna's megawatt radar pulses, you would be burned. Birds flying by energized jets like that drop dead from it quite often. So that gives us a clue now to the technology.