Default Is the back of the tablet scratch resistent / self healing or have I just jinxed myse

So I've had my notepro a little over a month, and the back looks pristine. The other day it got slid along a rough concrete floor, and I thought I saw scratches. I was unable to inspect it closely at the time and didn't want to make a big deal of it. Today I was looking at the back and it looks pristine.

Now, I keep it in a smart cover case about 50% of the time, but before I had the case I travelled with it cross country where it had the usual share of getting jammed into my bag quickly etc.

Is the back of this case self-healing to some extent like the LG flex, or is it just incredible resilient? I am expecting a skinomi skin for the back cover, but I don't anticipate it will stick very well.

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