Israeli spy planes over Budapest airport

The two Israeli spy planes noticed near Budapest Ferihegy Airport remain a mystery, at least to me. There are various guesses as to what they were doing in Hungarian air space, ranging form being on a "spy mission" to simply training. The spokesman of the Hungarian Defense Mission told media that the planes were on a diplomatic mission. They never landed in Hungary though.

Now I wonder why carry out a spy mission in such a highly publicized manner. They are supposed to be covert operations. But then again, how can planes of foreign states come and go in other states' air space. Why weren't they shot down to begin with? Or if they were authorized to be there then what is all the fuss about?

Could Hungarian spy planes (if there are any) hover over Ben Gurion Airport in Tel Aviv, on some sort of "diplomatic mission"?