How did Donald Cooperman get burned?

Neither were ever revealed.

I don't know what it means but...Cooperman had a dream of McBride flicking a lit match at him, setting him afire.

Since it is stated that he was behind the scenes at the firm he and billy started, and then that he had a big dinner including a message from the president when he came back from the vietnam war, it is pretty clear that he has burned in the war.

What is truly ironic, is that what likely burned him in the war was an accident with naplam. And then he is defending the guy dumping illegal napalm in the ocean.

I will miss these boards. F- you Amazon.

I understand. Thank you for telling me. -The masked bandit

I've been rewatching this show.
I'm speculating here. But in my opinion it seems like.
Donald Cooperman is and always was a narcissistic superior. Taking advantage of those with more compassion than him but they were also were highly intellectual.
Some employees about the cause being either the war or billy.
What if Donald and Billy were both in the war, together? Donald definitely being older and more ruthless was probably a higher rank than Billy. Before starting the firm.
And then in S1E6.
Donald has a nightmare about being burned by Billie. They both looked naked and in the restroom, almost as if they just got out of the shower.
If they both did serve in the military. Billy would know how to make something highly flammable put it in a container like body wash and conceal the order.
I think it is highly plausible that is what happened.
Donald has taken advantage of a lot of smart women, made them feel wanted and loved. Not to mention superior to everyone else they work with.
He probably did the same thing to Billy.
Only difference would be when the woman were used and tossed out for someone else, they didn't do shit.
Maybe. Billie didn't like being used and did something about it.