Ok - I've know some older folks and dogs in my day...My theory:
•Dog was hungry (so it's attentive)
•Old Lady - messy eater; had combo of gravy, animal cracker crumbs and prune juice drippings on her ankle.
Results - well, you read the story. LOL
As I understood the TV report on Fox, the dog was not entered in the show, it was just brought there by the owner, who didn't have it under his direct control.
I'm sorry for the lady. Akitas, in my experience, are aggressive by nature.