Gonzalez right now looks like a better LOOGY than Burnett. I think Burnett was more or less getting work in in a lower leverage situation. They wanted to see if he could be effective before they use him where the situation is more important.
Yes, it was a playoff game, so all situations are important. However, up 1-0 in games and down by 4 runs late on the road in game 2 is as close to low leverage as you are going to see in the playoffs. Gonzalez actually was in in the more important situation.