// First the tiles needed for the tree hash.
	th, err := HashFromTile(tiles[stxTileOrder[len(stx)-1]], data[stxTileOrder[len(stx)-1]], stx[len(stx)-1])
	if err != nil {
		return nil, err
	}
	for i := len(stx) - 2; i >= 0; i-- {
		h, err := HashFromTile(tiles[stxTileOrder[i]], data[stxTileOrder[i]], stx[i])
		if err != nil {
			return nil, err
		}
		th = NodeHash(h, th)
	}
	if th != r.tree.Hash {