So to recap the new info on facts/timeline that we have from Kim and Brooke, and Albert Young:
1) Tuesday: we know that after Steven was seen on the dirt road to Nua'ailua on Tue. afternoon, that he followed Brooke and Phaedra to their Haiku home, in his truck.
2) Kim questioned him there.
3) Kim let him take Zoe.
I seem to remember from his own interview that he was with Adam when the news came in about Nala. Adam and Fiona went out to Nahiku and arrived around 1 AM, per Albert who met them.
It does not sound like he had opportunity to go back to Paraquat's with all this, unless very late. Most likely this is when he burned the Forerunner, but where was it hidden if it was in the Haiku area?
Wednesday: Kim took back Zoe after the burned truck was found, and she felt lied to by Steven. He complained "this"'was getting pinned on him. (The next day he did the HNN interview.)
I sure hope he agrees to talk after he gets convicted.