For this achievement, you must have Heck sell you out to Hellbach at the end of the Taipei missions. The way you go about this is by making sure he doesn't like you, which isn't too hard. One of the first missions you have in Taipei is to actually meet up with Heck, but make sure you don't do that right away. Instead, do another mission before finally meeting up with him, and right away you'll lose one like point with him. Afterwords, just stick with mainly professional responses. Due to Heck's colorful "personality", Suave responses pleases him to no end, and Aggressive will every so often please him.
During the mission "Retrieve NSB Data from Grand Hotel", Heck will ask you to delete some data on him. Don't do it, and just finish the mission. Also, at some point or another, he will email you about his conspiracy theory. After reading through all of it, just give him an Aggressive response, and you should lose quite a bit of like points for both actions. If you've done everything correctly, after defeating Omen Deng, the achievement should unlock shortly after.
NOTE: Make sure that if you plan on going for this achievement, that you do NOT do Taipei first. Due to the way the game handles the final mission, doing Taipei as your first location ensures that no matter how much you piss off Heck, he will not betray you. Make sure you either do Moscow, Rome, or both before getting around to Taipei. Also, make sure that either Albatross and SIE like you enough to be your handler.