I was on a two-lane mountain highway last weekend going about 50-60 as per the speed limit when suddenly the cars in front of me slammed on their brakes. I went into emergency brake mode myself, kicked in some ABS, and swerved to the left brake down lane anyway (fortunately) as was highly fearing getting rear ended (I knew a big F-150 was behind me).
As that unfolded for me, two cars back you could hear their tires screaming to a screech, and then the third person back swerved and stopped behind me in that break down lane. I held my composure pretty good, yet was astounded by the close call and took awhile to process what happened. Traffic slowly began moving until I found out there was a random crash up out of sight up ahead that caused the slow down; then we all were back to 50-60.
I know many of us have close encounters like this. It was my scariest / closest one yet in my first year of riding. I'm thankful it worked out okay for everyone involved (no crashes at all), and we could all go home with normal days. I was definitely thankful I've practiced emergency braking and have kept my escape route training.
I've slid out from gravel / ice a few times and kept the bike up, too, but low speed / only me involved.