Here is the passage in question:

「では、「単一民族」発言はどうなのか、と問われるだろう。
この場合は、つい先日「先住民族決議」が可決されたことを受けて、「日本は多民族国家」であるという「事実」が確立しており、「単一民族」は中山君一個人の価値観という解釈になる。」

The post is quite long so I could only pick out a couple points, I hope I haven’t misrepresented the blogger’s position.

“The interesting question is whether it was a gaffe betraying the speaker’s belief that Japan ought to be an ethnically homogeneous country.”

There’s only one person who can answer that, and I doubt that he will.

The interesting question is whether it was a gaffe betraying the speaker’s belief that Japan ought to be an ethnically homogeneous country.