It's amusing to me how DNA evidence is accepted with very little hesitation in any number of circumstance. People going to and getting out of prison left and right. An ancient finger bone gives us a new hominin.
Enter Bigfoot and the stuff is fraught with problems. No one but Todd Disotell knows anything about it.
The DNA will be what science says it is. When there is contamination,they can tell. When it's degraded,they can tell. When there is insertions,inversions and deletions, they can tell.
You could have a mess to sort out, but it wouldn't publish without something conclusive.