Max prepared their official version of the mission report while they waited for the higher authorities to come to yell at them, then sent it off as soon as he was sure that his response, his report, and Nico's version of events matched up with what the Koleska would find on their sensor logs.
They couldn't see through the cockpit shielding of the two Mecha, so they couldn't verify whether or not he was remote piloting both Mecha, so that part was relatively easy. He could also explain away the combat capabilities as part of human technology. He would just have to pretend that he was actually apologetic for the Antimatter warheads since they posed a real risk to the stability of the nebula.
What he got, after the Koleska leadership had reviewed the situation, and the risk that the Arisen could have made it through to the other side without anyone to stop them, was a sternly worded memo.
That was it.