nayrt either, but "shrugged" can be used as a synonym for saying something indifferently without physically shrugging. using it that way would be a stylistic choice, and maybe not the best choice, but still one you'll occasionally see. i'd parse the passage on the basis of whether a comma or a period had been used.

if you want the example to be unambiguous, replace "Anon shrugged" with "Anon began to pace."