THIS INVOLVES MAJOR SPOILERS SO DON'T READ IF YOU HAVEN'T READ UP TO EPISODE 120.
Basically my theory is that when Eren told Mikasa he hated her for always clinging to him because of her Ackerman instincts...
1. He said this to push her away so she wouldn't get in the way of his plans and try to stop him.
2. He wanted to try to get her to break her habit of constantly trying to protect him once and for all because in truth, he desperately wants to be the one to protect her instead but he's never felt strong enough when compared to her.
3. He wanted to let her know that he was hurt to find out that the only reason why she shows that she cares about him (he thinks and I believe he's wrong) is because she is being "controlled" by her instincts and not because she actually loves him out of her own free will.
4. He actually hates himself because he thinks that he is the one who drove her to 'slave' after him and he wouldn't want to do that to anyone, especially Mikasa.
When Armin says "is that the freedom you wanted? The freedom to hurt Mikasa? Who's the real slave...?" You can see from his facial expression that he's about to lose his cool when he says "who are you calling a slave?" He's extremely hurt and not just because of what Armin has just said. He's hurt because he's reminded by Armin of how he hurt Mikasa and although he was the one to call her a 'slave', he can't stand to hear these words coming out of someone else's mouth, which means he wishes that what he's saying isn't true to an extent.
What is your take on this? And do you think we'll get an apology from him? Mikasa removed her scarf and left it behind before battle but she wasn't alone when she did so, another soldier brought this to her attention and Mikasa confirmed that she's leaving it behind. Is this closure for Mikasa to stop following Eren? Will Eren get hold of the scarf himself from the soldier who was with her and realise what he's done when it's all over? I think although the Ackerman instincts make Mikasa strong and protective, I don't think she would be as protective of Eren if she wasnt in love with him. She even tells him "it's because it's you Eren".