Why did the Fed-Ex truck spin out?

Why do I care about a fed-ex truck?

     The other day I was driving home from a dance show in NK, RI. I live way up north, so I was driving through the rain on 295N on this past Saturday afternoon. The rain was not coming down hard at the time, but there was a thin layer of water on the road and it was still raining a little.
     The car in front of me in the left lane was going about 75mph, I was going a bit slower than that. It was just us two, with a sizable gap between us and the group of cars behind us.
     Suddenly, that car in front of me started braking. I took note but was not concerned; I thought they were just adjusting their speed. When they had been braking for more time than anticipated, I looked up to see if there was a reason for them slowing down a lot.
     Well, the answer was h*ll yes! It was a Fed-ex truck careening haphazardly towards us on the highway! Having started braking to match the car in front of me, I thought, "Sh*t, I need to stop!" Luckily, the right lane was empty and as I hit the brakes I was able to move into that lane to avoid a fender bender with the car in front of me.
     The fed-ex truck eventually made it to the right shoulder of the road. I, meanwhile, tried to hit my hazard lights but instead turned off the engine of my car. So I'm sitting there, with my car in park...
     Now, there are a few things I want to know.

1. Why did the Fed-Ex truck spin out?
2. How much time would it have taken me to fully stop behind the car in front of me, if there had been no room to swerve into the right lane?
3. How fast would my car have gone if the car behind me hit me?

To answer my first question, I am going to calculate the maximum speed that a Fed-Ex truck should be driving in the rain.

On a road with a gradual curve of radius 222m and is slightly banked 5 degrees:

To figure out if I would have collided with the car in front of me, I am going to calculate the time it would have taken me to stop completely without swerving.

To answer the final question, I am going to use momentum to figure out my final speed after being rear ended (hypothetically; I luckily didn't get hit).

so basically I am one lucky duck that I didn't get hit

Citation:

http://hyperphysics.phy-astr.gsu.edu/hbase/Mechanics/frictire.html