Using the same premise, what's Biden's excuse then? He was advised by his general how many people it would take to secure the air base and the city and he basically over rode them and said he didn't care. Wanted to keep the numbers of personnel low and it snowballed a lot of what we saw unfold.
In reality, the POTUS does not unilaterally make the decisions to launch nukes. Its a process with multi-levels of safeguards.
At its simplest, what Milley did was violate his chain of command and committed insubordination which is subject to court martial. That is on the very simplest end of the scale. What he did was more dangerous than the story his is trying to say was the opposite. In a true scenario, the POTUS would not have the same direct path with no safeguards that Milley created for himself with what he did.