Autofeather at lift off under t/o power would be quite an event. Mind blowing confusion with Nh, TGT, FF all in t/o range. Hydraulics unlikely to have caused or contributed, it is the contradictory indications of a sudden and unexpected autofeathering that are a handful.
A good example is the accident report for Lockheed L188C G-FIZU, AAIB bULLETIN 5/2008.
For those interested:
http://www.aaib.gov.uk/cms_resources...ZU%2005-08.pdf