Dredging this conversation back up, but the way I see it, he's always blamed Xavier for Reggie's death, which is why he eagerly sold Xavier back to Resoom, but in this latest Interlude, Lance feels that Reggie's death wasn't Xavier's fault, it was his--that he didn't try hard enough to keep Reggie safe.
Regardless, yes, after Xavier he's handed several people (presumably Carriers) to Resoom, ending with Cyrus (though it failed), and now he only feels guilty that he hurt Cyrus because unlike with Xavier, Lance had absolutely no reason to hate him.