It is important that the other person/people on the winning team not go around killing the opponents to ensure that the intended player has the highest score. Whoever is going to unlock the achievement needs to capture all three points and then you can wait for 3-4 minutes for the victory screen - and achievement - to pop up. If you want to lock other people out, you will need two clans of four. Very few people play the multiplayer portion of the game to start with, and even fewer play clan mode, so this is the best way to ensure that you can successfully obtain the achievement without having other people join the game and interfere. For the public clan match you will need to have two people in one clan and two people in another clan, and then set your game type to Clan and Domination. If you want to earn it with friends, you can do it in a public clan match with 4 players.
You earn points by capturing control points and killing opponents obviously high value kills are more useful. If the team captain for that round doesn't choose The Jaguar as your playable character, you will have to wait. You can earn this in a public domination match by being the highest scoring player when your team is playing as The Jaguar.
