^This, and was there any fluid on the ground? Did the clutch pedal drop to the floor? Like he said, could be plenty of things, but hopefully it was just the slave cylinder and you can pull that crappy ls7 clutch out and replace it with something that will actually hold power if you ever plan on using that "lsx shootout mod." ECS makes a nice trans brace that would be wise to do if the trans/rear is out.
Even if it's just a slave cylinder, the entire drivetrain would still have to come out.