You should'nt have used an end event to finish the track... I did that too in one of my Evo tracks, but the finish times will round it out at ticks, so xx.016/xx.033.
When I looked at the leaderboard I thought it was just the cp bug, I had that too in my track Blugs & Glitches, but after I saw your replay I noticed it's because you probably used an end event. No big deal, but now you can finish the track like I did...

I think 50 sec is possible. Messed up at 2 points. You can see it in the replay. If it wasn't for the bailout, I wouldn't have beaten your time. :P
Edit: You can even bailout and finish the track from the first steep incline at the finish. But you have to get that perfectly. Don't know if you shave off time with that but if so maybe a second.