The sad facts are that, as you were good at your job, you were seen as a direct threat to the rice bowl of those less competent but slightly higher up the chain than you. You had to go and they had, I think, just been waiting for you to provide an opportunity. Otherwise you might have seen them out of a job they didn't do very well.
Hope you get your head-set back and a better job very soon. The operator owes it to you anyway, you saved them a lot more than its replacement cost. You didn't just lend it to the pilot, as I see it, but the company who owned the aircraft so they have a moral responsibility. No doubt 'm'learned friends' wouldn't see it quite so clearly!
