I think that it was exactly the same situation (or a very similar one) that happened with the Minbari , the trigger-happy and overconfidant Earthforce captain Jankowski misinterpreted (again) a first contact situation and opened fire on an alien ship , but without beggining a war , thus , the incident was overlooked by the (also overconfidant) Earthforce command .
BTW , the Dilgar war (or at least the human participation on it) was not due to an accident , but a deliberate decision , after seeing what the Dilgar were doing to the League races , and that their offensive was approaching human space .
For the Dilgar Adventures I am running I crafted the Omega Incident to be the EF hyperion cruiser Promethius pulling border patrol and filtering / guarding / inspecting all the refugee ships coming through a specific jump point. The Pyrotannia entered earth space just a few hours before a Dilgar Destroyer. Captain Jankausky spoke with the Dilgar ship and would not let them take control of the Pyrotannia, a diplomatic vessel full to the brim with various diplomats from all the systems the Dilgar had forcibly taken.
The Dilgar seeing only one EF ship, and being overcomfident, prepared to fire, Captain Jankausky simply beat them to the punch. However the battle between the two ships cost the lives of thousands of refugees as large ships packed full of aliens only wanting to live peacefully were in the words of B5, "Blown to Hell". My players were a bit depressed after the adventure. Seeing all the innocents lost, doing the right thing by defending against the Dilgar, and then Earth Force showing up and punishing them all. One line I remember was, wait, when did we become the bad guys.
Earth Force learning of the actions sent ships to relieve the Captain of command, and to stand trial for his actions. The incident labeled OMEGA, was so labeled because once the Abbai diplomats gave their report to the Earth Senate, Earth went to war. Thus the 'Omega Incident' was the Last Dilgar 'Incident' and the start of Dilgar 'battles' and 'skirmishes'.
But that's just my personal take on it. To add to a bit, I believe earth dispacted a ship right after that into dilgar space. The Earth Force rulebook gives the name of the ship. Needless to say, it was blasted into tiny pieces. Yet another reason to go to war.
EAS Prometheus fires on a Minbari vessel and kills Dukhat in 2245.
Is it me, or did Captain Jankowski not look old enough to have been a captain for at least 14 years?
In my mind, the Omega Incident was simply an isolated occurence: Regardless of whether he had been absolved from blame, I somehow don't think that Jankowski would have been chosen to initiate first contact with the Minbari if the previous incident had exacerbated the conflict with the Dilgar.
I gotta drop my two cents in and agree on the side of revenge. It just doesn't seem plausible that such an individual would be given the chance to screw the pooch a second time. Heck, I doubt they would let such an individual keep his CPT rank and then regain it. He would be unofficially cashiered out of the EarthForce.
Yeah, people, remember the time frame. The Omega incident must have occurred somewhere around 2240 - since Jankovski Really doesn't look old enough to have been captain for very long; so it was at least 8 years after the Dilgar were defeated.
And it was mentioned in the context of "Jankovski not doing well in first-contact situations" - meaning he must have screwed up one of those, in a way that left no doubt in the minds of many of his fellow officers that he was a "loose cannon" no matter that the tribunal politically correctly cleared him of all charges.
So I'd suppose it was most likely an run-in with some league race during the EA's "expanding their sphere of influence" period after the Dilgar war - most likely with some minor race that Jankowski found threatening and fired upon... but who were too small in B5 interstellar terms to do more then file a protest once someone better at FC established diplomatic relations... maybe a race not even having interstellar capability, just some system-defense ships... (because if they had interstellar capability the EA probably wouldn't have dusted off their complaints so easily - after all, they Were after allies and new races to establish profitable relations with) something like that. Pick one of the really minor races (those who were not likely contacted during the drive from Markab space to Omelos in 2231-32) from the map if you like... Kor-Lyan, Torata, Thrakallans, Moradi are possible, more likely Soom, Gigmosians, Krindar, Zanders or Zafrans... etc.