I'm curious to see what folks thoughts are regarding this item, but before doing so let me make one thing clear. I am not trying to point out errors or plotholes. In fact, I hope to show that the way in which this is occurring is not an accident or oversight by Kishimoto, but a large part of the story to be revealed later.
Here in 608 we have Kakashi's vest being slashed with an X across the front. It's kinda obvious, X marks the spot. It's huge and hard to miss.
The mark is in the subsequent panes for 608. Then in 609 we get a look at it and it's gone. It's gone in every subsequent panel for 609.
Now in 610 and, hey it's back again. No really clear shots of the front for the remainder of 610.
Now 611, and you guessed it, it's gone again. It remains gone in subsequent panels.
Now 612 and it actually is still missing. Not a lot of panels with Kakashi in this one but it is gone througout.
In 613 it is still missing and continues to be missed in subsequent panels.
In 614 it is still missing and you think well Kishimoto must have just forgotten about it at this point.
615 still missing.
616 still missing and it appears that Kishimoto is done drawing the X, and really why should he since it bears no significance to the story, right?
Any thoughts or theories? Clearly intentional and not an oversight IMO.