Is there a particular moment you're referring to? There are a handful of times, from what I can remember, that Asterion muses he's turning to stone, but it's always as a metaphor for his apprehension, not a literal transformation :)
Aha, that makes more sense. I had assumed it was metaphorical at first but then thought it was more literal when the game continued to describe an inability to move his body. I should have stuck with the first interpretation.
