Considering that Lincoln was dead long before the 13th Amendment was ratified, and seven of ten rebel states didn't vote on it until after he was dead you can't very well blame Lincoln for breaking the ratification process. Well, maybe you can.
You think Johnson pressured the army to do that? Lincoln made his purpose clear before he died.
On the other hand, do you think the Southern states did that voluntarily? I find that hard to believe, because the long standing narrative was that they fought a war or something to preserve slavery, so it strikes me as implausible that they would simply give up something they supposedly sacrificed so many people to protect.