So maybe someone saw that and assumed that the next logical step was that he become a samurai
The issue actually really stems from the fact retards often use knight and samurai as liberal translations.
In western culture knight is ambiguous because overtime it changed and has meant many things, from knights only being nobility and land bearing soldiers to being the elite vassals of a lord, but more often than not knights ended up as merely just soldiers.
In japan that's completely different as samurai were ONLY elites, samurai was the equialent of a title. it's quite literally IMPOSSIBLE for him to have been a "samurai" but western culture calls ANY noble guy with armor and sword a samurai, when thats never the case