I think all he was doing was pointing out precedent from similar projects, which is hardly "convincing himself he isn't a threat". There are many, many Star Wars mods across an enormous plethora of games (from Garry's mod to Fallout to Mount and Blade), and I've yet to hear of even one being shut down or sued into oblivion. Especially considering they are making their own models, audio, and effects, and not copying from any other game, and are non-profit, I don't think Disney would have any interest in stopping development on Imperial Assault, and although I don't have a legal background by any means, I am unsure as to if they would even have case or not, considering fair use.
Also, this is unrelated, but do you have a source on that 88 million dollar lawsuit against that private WoW server you spoke of? Considering that's probably in the rough range of what WoW pulls in quarterly, I'd be very interested to read the background of that suit and see how Blizzard apparently came up with that number.