I broke my brake reservoir off and it locked up my brakes too, but didn't know they were on all the way and headed back to the truck. When I took off after the accident the brakes were not on, I think I would have noticed, but it was getting dark out. Started smelling burning brakes and slowed down one time and noticed that the brakes were on. Happened to look down on the clutch side and realized that the rotor was bright red. Stop and threw lots of snow on the area to cool it down and it took a lot of snow. Pulled the bleeder valve and drained all the fluid and was then able to drive back to the truck. Didn't realize that the brakes lock up when there's no fluid, thought it would be the other way around. Guess I learned something that day.