must have been in slow motion

[Vladv1]

"I wanted to help Doug, who was obviously in a great deal of pain, but Gary and the unidentified man removed me from the van and put me into the stranger’s car. Out of the smoke and weirdly aimed headlights I saw a figure staggering toward us—the driver of the other car. He jammed his head into the car window where I sat, still in shock, and said with a big grin, “What’s happening, man?” You could smell the alcohol on his breath. I lost it. Somewhere inside I knew that Nicky was dead, that I couldn’t stop Doug’s screams, and that this drunken asshole had caused all this and didn’t even care. I went after him, but it must have been in slow motion, because before I could swing, I found myself back being pulled back into the car and then we were hurrying off somewhere".

"Rainbow In The Dark", Ronnie James Dio.

What does "must have been in slow motion" mean here in other words? Does "swing" mean "to hit" here?

 

[Tarheel]

If you move in slow motion you move slower than normal. If you take a swing at somebody you make an effort to hit him with your fist. If you were successful you wouldn't say that. You would say you hit him.