Collagen fillers after accutane

My daughter finished a 5 month treatment of accutane two months ago. Though her acne has cleared she was left with many scars. To address the scars her dermatologist used collagen fillers. Though the treatment initially looked like it was very effective, after only a few days the scars resurfaced and now appear almost worse than before. I have read all over the internet that no scar treatment should be started until 6 months after finishing Accutane however, two of the dermatologist she visited said that this warning was only a precaution and was just to ensure that there was no active acne. In her case, they said that it would be safe to proceed. Now I am not so sure. Is it possible that her reaction to the collagen was becuase it was done so soon after the Accutane?