Considering that you proposed killing a tree in way that specifically is aimed to to get around local regulations while hiding your actions, that does fit the definition of anti-social tendencies, so calling it 'sociopathic' is a bit of a stretch, but not completely off-target.

> a pattern of behavior characterized by a disregard for others' rights and feelings, a lack of remorse, and manipulative or deceitful tendencies.

You are talking about killing a tree in a deceitful manner designed to subvert local norms, regulations, and the concerns of your neighbors. You aren't the only person your actions affect (and you know this, because you opened your post by saying you should lie about killing the tree.)

I think the word fits quite comfortably.