Now, does it mean they see the Hadith as a “living document”?
The Hadith was arbitrarily adopted as "official" and "unchanging" by, among others, the first and most respected scholar:
This online version, translated by M. Muhsin Khan, has a useful table of contents. Bukhari included 7275 hadith in his Sahih, many of which were variants of others with different chains of transmission. Of these, 2712 were not duplicates. It was reported that he had originally collected 600,000 hadith before subjecting them to his critical method.
LINK
Obviously, if muhamed spend his entire life just dreaming up "wise" sayings, he would have had no time left over to kill anything, rob anyone or organize a killing machine, even if he lived to be 200, which he didn't.
Bottom line, the human process of picking and choosing is subject to all the scams, power plays and outright dishonesty humans are subject to.
Quis custodiet ipsos custodes?