Over the last two weeks, I've been discussing the Big 12 tie-breaker and texas' situation with wishiwasalonghorn, and he is adamant that the resolution of a tie in the Big 12 shouldn't be left up to people outside of the conference, i.e. voters who are coaches of other schools and voters who are members of the media. While I believe OU won the tie-breaker because they were lucky enough five or six years ago to schedule a Cincinnati team  which ended up winning the Big East, and a TCU team that finished second in the Mountain West Conference, I can understand his point. Leaving the decision of who will represent a division in the Big 12 Conference Championship Game partially up to people who have no ties whatsoever to the conference does leave a bad taste in your mouth. With that in mind, I think I may have some up with some options for a simplified solution to the breaking up a three-way tie in division play in the Big 12 that is completely conference-centric.

1. Margin Of Victory Is Everything: Since you are dealing with three teams who all lost to each other, simply take the team who had the largest margin of victory in their game against the two other opponents, and that is your representative. In this situation, OU still goes to the Big 12 Championship.
2. Margin Of Victory Elimination Plus Head-To-Head: Take the team who lost by the biggest margin to one of the other two teams, and eliminate it. The winner of the head-to-head match-up between the two remaining teams is the division champion. In this case, Texas Tech is eliminated because of their large margin of loss to Oklahoma, and the head-to-head matchup between texas and Oklahoma decides the winner. In this situation, texas goes to the Big 12 Championship.
3. Ratio Of Dominance Is Everything: Go back and look at the games between the three teams, and determine which team was more dominant in its games. Dominance will be measured by what period of time during games a team held a 17 point or more advantage. I chose 17 points as the baseline because it is a three-score advantage, and reflects clear superiority.  You go back and look at the box scors of the games, and the team which led games be 17 or more points for the longest period of time goes on to represent the division. If no team has a 17 point lead in their games, you go down to 14 points, then to 10, and so on and so forth, until there is a base number for a comparison ratio. Under this plan, I believe Oklahoma would still represent the Big 12 South as division champion.
4. Ratio Of Dominance Plus Head-To-Head: Use the Ratio Of Dominance figure to determine the team with the least amount of time of dominant play, and eliminate them from discussion. You then go to head-to-head results between the two remaining teams. Under this criteria, I think texas would have been eliminated because they trailed both Tech and OU for portions of their games. This would leave the Tech-OU head-to-head matchup as the deciding game, with means OU represents the Big 12 South as the division champion.

So, there you have it: four options which gives you an easy way to break a three-way tie, and send someone to the conference championship game. Best of all, none of the tie-breakers depend on a poll of outside voters or other interested parties to determine the winner. The only potential problem I can see is with the margin of victory criteria, because some will say using it will make teams run up the score more, but because we are dealing with teams that in theory are pretty close to each other in ability, I don't think you'll see huge margins of defeat in that scenario. In any case, this is football, not tiddly-winks, and it is your defense's job to stop them, so suck it up.