I see this has not been posted here yet. It has been in Hammer and bolter but for those, like me, who does not purchase them, here is the short story. And i do have to say it is definitely one of his(if not the) best fictions to date IMHO.
"This short story originally appeared in Hammer And Bolter, a download-only fiction magazine from The Black Library, bringing the worlds of Warhammer and Warhammer 40,000 to life. Hammer And Bolter showcases all of Black Library’s new authors and has full stories by established guys such as Abnett as well.
"The Strange Demise of Titus Endor" By Dan Abnett