I'm trying to find where the first contact happened. From the 3 camera angles I can find, it looks like Burka had the first contact.
Feet from the rear: Watch the feet from 32-35 seconds.
http://www.youtube.com/watch?v=1DIaob7a8Ik
From this angle it looks like Burka is already way off balance before any feet or legs make contact between the two.
From the rear: Watch the hips from 32-35 seconds as well.
http://www.youtube.com/watch?v=1DIaob7a8Ik
Again- it doesn't look like the hips are involved in the collision until after Burka is way off balance. From this angle, it is pretty clear to me that Burka's balance is thrown from something occurring above the waist.
Arms: Watch Burka's left arm starting around 52 seconds.
http://www.youtube.com/watch?v=1DIaob7a8Ik
She makes 1, 2 normal arm pumps with her strides, then the third, just as Rodriguez is adjacent, looks like she throws an intentional elbow, then goes off balance.
Now look at the Day 9 highlights at:
http://www.youtube.com/watch?v=1DIaob7a8Ik
Here, it looks like Rodriguez has the hip clearance (about 52 sec in), but Burka goes wide with that left elbow, smacks Rodriguez, and this leads to Burka going down.
From this, I'm pretty convinced that Rodriguez didn't push through- but rather Burka threw a wide elbow, upon impact, this threw off her stride, and she wiped out. Rodriguez only goes off the track to avoid the falling runner- something likely not DQ-worthy.
Very tricky call- I'm not sure they got it right.