What is the logic here?

1. It is a (alleged) fact that Margaret struggles to write coherent sentences.
2. Therefore her claims about her Photoreading performance are open to question.

I have difficulty following this. It's possible that one is performing Photoreading at high levels for the sake of learning how to be a better gardener, not a better writer. And if one were Photoreading to become a better writer, it does not follow that one's poor writing undermines the claims of Photoreading. It's possible that one is still reading quickly with high comprehension. It would call into question some of the claims of "direct learning" of new skills.

So, Sidis, please clarify.