Perhaps someone could dig throught the forum for a relevant topic with ktom's explanation.
I went through all the "Rules questions" and I found this topic which confirms you are correct:
It's also worth noting that since the Crone places the character in the dead pile from the discard pile, the Sellsword was never "in play" during that interaction. So even if placing in the dead pile counted the same as killing (it doesn't, as mplain says), you still couldn't get the 2 gold because you can't trigger his ability when he's not in play.
Btw is there some new info on this topic?