I've been looking into this a lot more deeply, and I am fairly confident that this is a spurious, non-hostile occurrence. I can't be 100% sure, but a multitude of factors: Arthur's response and his good attitude, the detail of the logged message itself when cross-checked against a few 'expert' sources, and the fact that it only happened to Arthur once, and (apparently) nobody else was physically ejected from the server at the time.
I'm not sure whether someone ran a script on Arthur (it's plausible, but I cannot prove it one way or the other), nor am I sure whether it was a side-effect of a server-restart and Arthur being 'first on' (sometimes the mission ends if everybody is still loading the pbo file at the point where the mission believes it should begin running).
In a nutshell, I'm going to give Arthur the benefit of the doubt.
Hopefully you, Arthur, can see that when we see 'footprints' in the hack detection-logfiles, our first duty is to ban and remove the threat, and then unravel the incident if the person comes forward to claim their innocence. This way, the most number of people are protected first, and quickly, even though it may turn out to be at the expense of someone who was innocent. Most often, of course, the accused person never shows up to defend themselves (a sure sign they're guilty!) but sometimes, when they show up, like you did, we will dig deeper and try to pinpoint the exact cause (if we can), and take a view based on the person's postings.
So... I'm just about to remove your info from the ban-list file, and you should be able to get back on the game within the next few minutes.