In general for the future: if you have to go afk either dock on a base (which in your case would have been an easy solution), fly about 30 K above/below plane or make 100% sure that it is very unlikely that you will run into anyone while being afk.
They were within their rights and I'd even argue within rp-reason. If being mute would protect you from being pirated and destroyed we could also just remove every piracy line on every ID, because everyone who would get pirated could just ignore the pirate.