Oliver had decided that it was past time to become more proactive, both personally, and as a representative of the League. He hadn't been officially voted their leader, but he had leadership experience both with the League and as a businessman. He liked to think that he was growing up and had come a long way from the underachieving party boy he had been in his none too distant past--and though he knew he was a work in progress, he hoped that it was at least partially true.
So he had called Jack and arranged to meet with him in person, rather than relying on Zatanna to act as go-between.
He was very focused as he made his way to Jack's office that day, and arrived fairly punctually, and with minimal stress as he was shown into the Mayor's office.