Ryu, well, I came across different affirmations during my research, mostly by japanese scholars like Kenji Tokitsu. It seems the ideal image of the samurai we have a largely wrong, and we seem to forget that there really were two samurai era, and not a continuity: Bude Jikai (1192-1603) and Kamakura (1603-1868). Kamakura samurais were wussies compared to the Bude Jikai samurais, and yet our common conception of the samurai is that of...the Kamakura.
I won't dwell into that and I'm certainly not interested in a scholar name dropping.

The information is here, indeed, yet history is often an embellished lie agreed upon...so it can be tough to have certainties on some topics...