The only DNA "evidence" I know of is the researcher who found DNA from an extinct polar bear in hair samples (allegedly from Yeti) from the Himalayas.
'Evidence' pops up all the time, and usually the word they like to use is 'inconclusive'. This means nothing - could be that the DNA is degraded (which could come from anything, like heat or being eaten by microorganisms) or that it's contaminated. Contamination is is a huge problem in DNA analysis - most of the early efforts so to identify old DNA were bedeviled by contamination problems, years of results had to be recanted. Whenever I hear some new result of 'primate DNA' from a bigfoot sample, my first and only thought is 'of course - the guy running the sample is a primate'.