An upturned tortoise is helpless and vulnerable, so by rendering the monster like an upturned tortoise, he is making it clear that the monster is helpless and vulnerable.
Context: By rolling onto his back and holding Joey in front of him, he made the monster helpless.
Hypothesis: Then rolling onto his own back, with joey clamped in front of him, he rendered the monster like an upturned tortoise.

Given this context, is the hypothesis true (Yes/No/I don't know)?