Starboard vs port tack is fairly irrelevant (it would relate to how much room you have to give). The responsibility of keeping clear and giving room depends on the position of the boats when they entered the two-boatlength circle. If all three of you were overlapped, regardless of tack, the inside boat is entitled to room to round the mark and the outside boat(s) must give room. For the boat to leeward of you, he must give both you and the port-tack boat room. Which includes enough room for the port-tack boat to gybe. If the port-tack boat was not overlapped inside of you when you reached the two-boat circle, then he is not entitled to room.
However, collisions are to be avoided at all costs and I believe you may both be thrown out if the collision was sever enough to cause substantial boat damage.
Someone should have protested.
sm