I actually read the paper.

It might also be argued that people playing with computers cannot help behaving as if they were playing with humans. However, this interpretation would: (i) be inconsistent with other studies showing that people discriminate behaviorally, neurologically, and physiologically between humans and computers when playing simpler games (19, 56–58), (ii) not explain why behavior significantly correlated with understanding (Fig. 2B and Tables S3 and S4)..."

((iii) and (iv) apply to the general case of "people behave as if they are playing with humans", but not to the specific case of "people behave as if they are playing with humans, because of empathy with the computer").