“in his own blamelessness.” This seems clearly to be a place where the Hebrew text was corrupted, because it reads, “in his death.” But that reading is contrary to the message in Proverbs and indeed contrary to the teaching in the Word of God. Godly people don’t take refuge in death, they try to stay alive and serve God. The Septuagint and Syriac read “in his integrity [or innocence, or blamelessness]” and many scholars and English versions support that reading. Especially in light of the first stanza in which an evil person is cast down by his own evil, the righteous person can take refuge in his blamelessness.
Some English versions that keep the reading “death” as per the Hebrew text try to rescue the message by altering it somewhat, thus the NET has that the righteous have a refuge even in the threat of death; or the KJV says that the righteous have “hope” in death, but neither of those are what the Hebrew text actually says. Versions that recognize the Hebrew text was likely altered and thus say something akin to blamelessness or integrity include the BBE; NAB; NJB; NRSV; Rotherham; and RSV. To switch the Hebrew text from “in his integrity” to “in his death,” two consonants in the Hebrew word must be switched. The Hebrew bmtw must be changed to btmw, and many scholars feel the switch was unintentionally made in the transmission of the text.