The person driving the R/W/B Miata has stated that the cause of the incident was Denise making a hard right into him trying to take away his apex.
The video from Denise's car shows no manuevers at all through that turn. She was behind and slightly to the right of Ed when her car take a solid hit from the right and shoves her to the left. Her turn was even, smooth, with no sudden movements right or left until she was hit.