From the way I saw it, Rimi didnt actually try to make the other party win. I think she was trying to be fair and not win the game by hook or by crook.
I think she felt she had mate packets, while Prince got less, so she offered.Again when her team members put water in the milk to increase the volume, and then picked up already discarded packets to claim as new ones - she must possibly felt amiss. Later when she passed Prince's packets, while her team mates were shouting to reject, her logic was Prince passed some of her very small packets too. So all in all she was not being nasty, I felt she was trying to be fair. At least she played the task - and that too quite well.When Prince threw the bucket of milk of the opposing team, Rochelle stopped her team members from filling in the packets and said let them fill their bucket first, then we will fill the packets. That was also her being fair.