did the same thing at the track over the spring. as soon as i felt the car lurch forward and realized wtf was going on i popped the clutch in, i saw almost 8k before i caught it. besides leaving a flat spot in my drag radials when my tires locked up which scared the crap out of me... my motor and trans
are fine. not somthing you ever want to do but it can happen if your trying to shift fast and pull back the wrong way.