As for the distinction, there's so many other factors, like how well you do on your scales, aural and sight reading, etc. I think your style and interpretation is important too, besides having a perfect performance that particular day.
I didn't pause for 3-4 sec, but I did pause for about 1-2 sec once during my Grade 8 since my left/right hand were out of sync with each other, and I still managed a 27/30 on that piece. Don't worry too much, I'm sure you did fine.