What you have highlighted there are bag marks, which are not considered wear. If you are grading the coin AU, then by definition, you are saying the coin exhibits high point friction (wear). Now you can disagree with the assigned grade and say that based on the severity of the marks, you think the grade of the coin should be lower than MS64, but the furthest you could go down would be MS60. The coin in question is one that I used to own and that photograph is mine. Here is what I can tell you about that Kennedy Half Dollar. The coin had amazing gem grade luster in combination with the most vibrant toning I have ever seen on a Kennedy Half Dollar. The eye appeal of the reverse of that coin was off the charts. The coin had what I would consider MS62-MS63 surfaces and was market graded to MS64 for the exceptional toning, luster, and resultant eye appeal.
The toning on both of those coins looks absolutely genuine to my eyes. What reason do you have to think that either has been artificially toned?