I think I have a pretty good idea of how this mistake happened. ESPN contracts a third party company called Sportvision to superimpose the first down lines and other graphics onto the field. So there's a non-ESPN employee sitting in the dome somewhere who is ultimately controlling this. He is the one who probably goofed and put the wrong logo on the field.
Of course I'm not saying ESPN isn't to blame. It's ultimately their fault. They should have quality controls in place that prevent this from happening and someone should have noticed it during the game and corrected it. That just seems like the most logical explanation for why only that logo was wrong.