Close call car accident. Who would have been at fault?

Okay so I was driving on the freeway to school today. As I was nearing to my school on the freeway I look to my left and see a car swerving, like totally lost control. It almost looked like he was intentionally trying to hit the car on his left but he definitely lost control. So as he lost control he swerves into my lane and I have to basically hit my brakes really, really hard so that I don't t-bone his car. I was literally about to drive straight into his car on his penger side. He actually ended up in the lane on my right side facing the opposite direction! I just want to know if like I would've been at fault or something because I have only been in one accident before. It was a reall really close call and I had like adrenaline and everything!