clutch question



i was racing a friend on his 400ex with my blaster, we were doing alot of hard cornering, and some jumps, and some straight aways and alot of top speed racing.well he slowed down and i went ahead, it had been about 15 min after i pulled it out of the barn, i started down the road and was going full blast, i let off and pulled the clutch in and shifted down to first with the clutch in and coasting, all of a sudden, i lose all of my tension in my clutch and it catches gear and i slow down fast, so now i have no clutch, i powershift to 3rd and drive back to te house. i pull my clutch cable out and unscrew the adjuster on my lever and now its fine, but what cood have caused this
it happened in a split second, all of a sudden the cllutch is fairly new
part of the break in process, my buddys 450R did generally the same thing but instead of not working at all it just started slipping when he pulled the lever in, then when he re-adjusted his cable its been fine ever since