: Haven't read it yet, but:
: http://halosm.bungie.org/story/newssearch.html?newsitem=1005
: http://carnage.bungie.org/haloforum/halo.forum.pl?read=751160
I scanned it quickly. As best I can tell, the one sentence version is:
"Durandal escaped the closure of the Marathon universe thereby inserting him into the Halo where he now exists as the Flood."
Personally, I would have figured that we would have been the ones to escape, if anything. I doubt Durandal had planned for us to be there in the end.