Answer (1 of 14): The term “continuity error” gets thrown around a lot in reference to Trek, oftentimes erroneously.
Some of the most famous “continuity errors” can be explained with a little imagination and common sense.
WHY DOES KHAN KNOW CHEKHOV IF CHEKHOV WASN’T INTRODUCED TO STAR TREK UNTI...
The best part of DS9’s Section 31 was that Section 31 knew they were the bad guys too.
Yeah, and they also seem believable as a rogue clandestine agency that the Federation is ok with having on “their side”.
Unlike the Obsidian Order or the Tal Shiar, the Federation has plausible deniability regarding the use of Section 31. Few powers seem to even know the agency exists.
And unlike the Obsidian Order or the Tal Shiar, Section 31 does a good job at being a clandestine agency. The Obsidian Order and Tal Shiar’s response to the Founders was to build a lot of ships to bomb a homeworld, something outside their expertise that gets them destroyed. Section 31, instead, genetically engineers a virus that attacks the Founders, a virus so effective that the cure is used as a bargaining chip in getting the Dominion to stop the war.