I agree we should expect better from a pro but I am willing to leave some room for "I was nervous and lost my place" , or " I was thinkin about the improvisations I was adding and forgot where I was in the song". etc. Making mistakes is human. I even made a mistake once when I thought I had made an error but really hadn't.
Everyone makes Mistakes , it doesn't make them unAmerican. Let he who is without sin cast the first stone.