Leave him be. There is nothing wrong with announcing a Dharma event or book if one thinks the blurb promises a good read.
If the post in this category of 'Book Reviews' is causing hyperventilation - then have a 'Book Announcement' forum or move it to the Lounge.
One should refrain from biased judgments and doubting in fathoming the Buddha and the Dharma of the Buddhas. Even though a dharma may be extremely difficult to believe, one should nonetheless maintain faith in it. Nagarjuna