If memory serves right, the only recent-ish R22 incident where ANR *may* have played a part is where an experienced fixed wing pilot oversped an R22 to the point where the tailboom fell off.
ANR was suggested as a possible factor but I can't remember precisely why.
Just found the accident link -
http://www.aaib.dft.gov.uk/cms_resou...pdf_501499.pdf