I may be mistaken but wasn't this guy mentioned during the Gathering Storm? One of the warriors that Trazyn set loose to defend Cadia?
I looked into it a bit earlier. There's mention that is could be a huge-even-for-a-SM BA sgt in service to the DW. However, there were Salamanders released from the tesseract on Cadia, so it just being a common-or-garden SM wouldn't really be worth mentioning them in the codex in the first place. There was also a custodes let loose from his tesseract on Cadia, so that's another possibility.
It is a nice idea though.