Just as Lex was getting ready to teleport over to Cassandra, he received a few reports about issues occurring within the Midnight Games. Although he had taken precautions to avoid external interference on the planets, no preparation was perfect.
It seemed that certain people participating within the Midnight Games had received external bribes from people who had ulterior motives for some of the planets where the war was occuring, or the participating planets. War time was perfect to conduct sabotage and assassinations, and so people found a way to make it happen.
The most ideal thing was for the assassination targets to die during the war itself, which was easily achievable. Many times, the assassins didn't even need to strike on their own. They just needed to ensure reinforcements would not arrive in a timely manner if their targets were under pressure.