Well, there is one solid piece of evidence that may not totally say it's Rabukan (the Druddigon in question), but then it's still between Zamsi and Rabukan. Keep in mind: That's only one list. Zamsi may merely not have gotten his ties done that day, and Zamsi also mentioned he doesn't really enforce a dress code in his workplace, meaning that for serious business (that isn't bowling) he may wear things that formally.

Stalkers are masterful liars. We were, at a time, totally unconvinced of Daz the Dragonite despite having talked to him with another Dragonite, AKA as good as it got. We must assume that they may give us pointers if it helps deflect suspicion. Embalm in particular isn't 'fighting' it, from what has been said; only Annul and Philter are known 'fighters.' It may be that Embalm massively enjoys their situation and thus doesn't want it to stop. I'm not saying Rabukan is on our top list of peeps that are probably Embalm, but that conversation honestly doesn't do enough to negate Zamsi as being it either.