Almost got in an accident. Need Advice

[LowchevyII]

So today I almost got into an accident. A guy pulled across 3 lanes of traffic in front of me, so I slam on my brakes from about 35 mph and swerve to avoid him. In doing so, I popped up on the center median. Once stopped, the other driver got out and asked if I was ok and all that jazz. I quickly checked over the car and it seemed ok (there was no collision thank god). I was still in a bit of shock and with traffic quickly backing up we both got in our cars and went on out way. It was only after I began to drive did I calm down enough to realize I should have probably got his information. I did however take down his license plate. I also realized though no physical damage can be observed my alignment is potentially screwed. Being that I didnt make a claim at the scene nor get his information, am I out of luck when I more than likely find out there is damage I didnt catch and or need an alignment? Any advice is greatly appreciated.