I expect it was more about 'proving' to himself that he can control it than showing you.
I was a daily drinker to black out and pass out. When I quit withdrawals were like a mild flu for about four days. Far less than I expected. It varies a lot.
However, the killer hard part is the mental BATTLE going on 24/7 in your brain. I expect knowing he had a set time to do, he could white knuckle it through but no way would have been able to keep it going. It is mental agony!
As drinkers we will go to any lengths to prove to ourselves that we don't need to quit. We do! Desperately. But we don't want to see that.
My AH does similar 'games' to this. Is all to fool himself. Best thing to do is detach and let him get on with it. Focus on yourself and your life. This is what I do and it works.