Had someone over the weekend play The Oath like turn 2 with nothing but one hero and one creep there. He ended up having to keep putting heroes there that the other two lanes pretty much fell easily.
The person was like level 19 too. I was completely confused. I just blocked it with one hero and took the other two towers easily.
The Oath feels like a really high skill ceiling card to me. Played in the right situations, it's as devastating as Time of Triumph or Emissary of the Quorum while costing only 3 mana. It's hard to play it right though.
I had a game where the opposing player dropped a turn 1 Oath in the right lane and put 2 heroes there. I just let Kanna chill there for several turns and used DP and Prey to spawn creeps to soak the damage and go wide without fear of them playing board clearing spells. Equipped her with Phase Boots so she was never in their line of sight. By the time my opponent realized this wasn't working and ganked Kanna, I had gone wide enough to take that lane while having a 4-on-3 advantage in the other two lanes. Tinker's signature would have countered that but he wasn't in the deck.