In real-time I thought Elston hurt him somewhat purposefully. Honestly did, and I expected to see that confirmed when watching this replay.
However, watching that replay several times you can see that the twisting injury occurs right as and right after Brown comes down (picture provided) and Elston is laying on his back and tackling momentum is pulling him back over his head. Brown even starts to wretch forward and reach before Elston even flips completely over and lays on him.
I'm sure Elston holding on through the tackle is actually what caused it, but I don't think his post-tackle actions did anything, simply because Brown was reaching for his leg before Elston was even laying on him. And if a dirty play by Elston caused it, I'm sure you'd have heard something from Richt already.
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