I find it hard to believe that in the middle ages they would have wasted good vellum for wanted posters for a population that was 99% illiterate. Also, didn't those posters looked printed--I can't imagine the poor scribes/monks churning them out by hand. Also, at some point Robin says to someone and and I paraphrase: "Did I do something to you in a previous life?" Even a sojourn to the holy land at this time would probably not have exposed him to reincarnation. Even if it did, it is highly doubtful that a Christian from the 13th century would have adopted or incorporated this belief into his everyday way of thinking.