How Can Be This Coin Graded MS-65?

That is not a finger print. It is textile toning. Textile toning is the type of toning that takes place when a coin rests against the mint bag. This type of toning is rare and not to everybody's taste but it is not a finger print. Now having said that, I see that Rick Tomaska is selling an Ike in a PCGS holder that does have a finger print. So your question is not moot, PCGS does let finger printed coins through from time to time. As to why that would not be a grade limiting feature? Who knows. It certainly would hurt a coin's eye appeal, in my opinion.

I looked at it quite closely and, frankly, I think they docked the grade for the toning. I don't see a whole lot, aside the toning, keeping it from 66.

I feel 65 was an accurate grade. I see cheek marks that would keep it from a 66.

As far as the possible fingerprint, I have an 1893 PROOF 64 Morgan where you can slightly see a fingerprint and the coin CAC'd. I suppose fingerprints don't really affect the grade?