Then perhaps you should present it as an unsubstantiated claim, and not a fact.
Didn't I? Don't decide on the veracity of something before reading the whole of it. The postscript is just as much a part of my statement as the rest of it, and it's much clearer than injecting numerous "maybe"s any "perhaps"es into the text itself.
Yes, it was presented as a fact. Prefixing it with, "this sounds cool but I have no idea if it is true," would have made it honest but reduce its directness.
Also, "postscript", something which comes after the main statement. That it changes the basis of the statement itself, could be called a linguistic hack.
In the 1800s they used to enlist prisoners to teach the newly-minted public schools, as their community service. These people had absolutely no qualifications to teach; however, the children produced from these schools were more equipped for the world of the time than any child today. (This is something from Gatto, so I have no idea if it's true, but it's a good argument if it is.)