And why would a civilization that literally is a crime syndicate exile a black market trader and information delaer? I mean, their civilization is made out of such people!

Hey, thanks for the report!
Crime syndicates still have their own rules and laws. So maybe he was from a black market, which is an illegal one by the standards of a crime syndicat?

I will forward it to the team, so that they can take a look

Or maybe it is because the event is not blocked by the code to apply crime trait and the RNG selected it for that event 

To use a tittle/quote of The Bard's "Much ado about nothing"