Your time seems to be around 8.400 which means that you are about 0.140 behind the top which again equals 17 ticks/moves. You don't actually have to make that many errors to lose 17 ticks.
When working on a better score you just need to do the best time you can with the method you have and then just think the method over and find the places you can improve on and then try to execute that method to perfection. Then rethink if needed. I don't think there are any big secrets you are missing, it's just a few ticks here and a few ticks there.
I had played this level for years and I still came up with a better method. That's the beauty of bd4.
You should be able to better your time with a little thinking quite easily but the last few ticks for me at least were pretty tough.
Good luck dude