Why wouldn't he land there? If he plans on creating some sort of surprise element, he could do it. As for the audience, if the SFX is translated, like the above, would actually be the explanation.
The him landing there was more of a joke XD
But as for what I said about the audience being confused; that was the only panel with this "mystery" person. There may be a translation of this person "landing", but lets just assume it is Kakashi. Now, given the circumstances, its pretty well accepted that Kishi can't focus a single chapter on anymore than 2-4 characters. If he gave significant panel time to anymore character than that in a single chapter, the plot/action wouldn't be able to move since theres so much going on right now. So assuming that the person you pointed out was Kakashi, let's say it takes Kishi 3 more chapters to bring the focus back to Kakashi. It wouldn't matter what Kakashi did (if he attacked/interrupted an attack/talked/etc), we the audience would be confused on when Kakashi get back, and there would be no way for Kishi to tell us that this panel is in fact when he got back.
Since there is no clear identification on this person, it can't be Kakashi. Because, in terms of panel time, too much time has already passed for our confusion to be too significant. If Kishi had shown ANYTHING more to hint that person was in fact Kakashi, it would have had to happen within a few panels from that specific panel in order for the audience to think "Oh! That person in that one panel must have been Kakashi!".
