This mission IMO was tasteless as hell because:
-Trevor is all about cutting loose ends, yet he let the guy walks...
-The whole torture scene was out of nowhere, I mean, I had no idea I was going to torture the guy before hand, the mission just didn't fit with the story at all;
-Trevor states that torture should be for the torturers, yet he was having a lot of fun torturing the guy...Does that mean the he would enjoy being tortured too?
-This mission's main purpose was to convey a message that torture doesn't work, yet that message backfires HORRIBLY because, well it worked, Mr. K gave the alleged terrorist location in the end.
The message would be more powerful if the torture didn't worked at all, Mr. K died and nobody would be able to figure out the whereabouts of the terrorist. Now THAT would show us that torture doesn't work;
The point of the mission is to show that Mr K would have said all that in the first place even without torture, also
Trevor indeed states that torture should be for the torturer BECAUSE he thinks torture is fun.