Huh, that normally isn't supposed to happen.

So if I am understanding it correctly, you defeated the raid on the Grove, right? Like, had the actual battle or did you assassinate Gut, Minthara (or KO'd her) and Ragzlin? Cause normally, like people have mentioned it before, Halsin, if you discovered Kagha's Shadow Druid plot and shared that knowledge with him, is giving her a very stern talking to and demotes her, sort of. So if that had happened in your run and then Kagha somehow reset to blaming you, then... that's definitely a bug.

As for Wyll's reaction, he generally hates killing 'innocents', fighting Kagha means a ton of innocents will die. Not to mention siding with goblins, as I am sure you well know. It's the only time in the game Wyll actually remembers that he's supposed to be a 'folk hero' and grows an actual back bone.