Sorry to over extend this, but...
It also strikes me that what we've seen so far is Aaron continually dancing around the issue of whether one fully sapient anthro would eat another: He stopped short of making us totally certain Cliff would have eaten Holly, and he avoided going for it in Unity because he felt it made the lizards too beholden to their instincts, I seem to recall.
I almost get the feeling he's undecided on it himself, wavering back and forth - maybe this is the arc where he commits himself, maybe this is another "maybe". It would be funny, however, if we think we get an answer in that the pig thing turns out to be a massive fake-out... and then at the end Velda eats Jackrabbit in the ultimate irony of his philosophy (maybe she's got some kind of predator-supremacy thing quietly going on?)
Apart from that, I have to say, I still think that if there is a butcher, all processing, cooking and consumption will be taking place in one place that acts as an "evidence trap" if they have any sense at all. In a small, enclosed place like Endtown with no room to put much distance between yourself and a crime or evidence of it, you do not want to give control over anyone else to things that might incriminate you; you want to make certain they're dealt with in a manner that you can be confident is final, leaving no loose ends that might be unravelled and followed back to you. In that case I can only assume the skull is a result of someone taking something home they weren't supposed to, and then panicking, or a botched disposal of some kind.
I still think Walt finding the skull was too much of a coincidence, though, and that he was set up to find it by someone. Doc specifically says the skull was heavy enough to be on the bottom of the canal, and while Walt could have been dragging his hook, I'd think a line intended to be grabbed by a friendly anthro fish would probably be floated somewhat above the bottom for convenience.