I disagree. I watched fairly closely as well, and I actually believe you can see where she either fell or stumbled. At the 1.1K mark, she is on the outside with her other teammates...she is furthest to the left. At 3:40 she is running slightly behind Bush (I believe) and then a second later disappears (as I believe the runner directly behind her does as well). Another runner comes in front and blocks the view though, and the camera starts to get blurry. But Tuohy doesn't appear to be beside or behind her teammates immediately after that.
At the 1.7k mark, you can see Tuohy working her way back to the front along the outside to pass others. At one point (around 5:34) you see her clearly go far outside to pass....if you look across, she probably still has 70 runners in front of her.
So to get back to 47th at 2k she had to be coming back hard.
Looking at her splits, it would almost appear nothing happened...but I have no doubt that she did fall and had to make her way back up. That's quite impressive on her part.