I guess he's also letting us know that he wasn't cluing Casino?
Well, I wasn't originally. Howeve, had they not guessed Casino for me, my gameplan based on your conversations had been to give the clue "Bones: 4" this time.
Yes, the original 3 were Spine, Whale and Goat. I didn't really make the strong connection to Whip or Casino (although as soon as Bones -> Dice -> Casino was brought up I cursed myself because Casino was my struggle word), but you all put the connections out there with almost no other connecting options. Since you guessed Drill (neutral), and Swowl's team removed Fan (blue) ... there was almost no risk in re-cluing to Bones.
I was very happy with the opportunity to play such a unique clue. While a team isn't allowed to direct their Codemaster (you can't say... "If it's Grape, code purple next round"), the codemaster is often (and usefully) influenced by the thought processes of their team. For example, if Grape is the assassin and my team is thinking "Tomato or Grape (even though I want Onion), I very well might clue "Fruit: 0" the following round.