The spelling of Marshall's last name changes throughout the series. In Season 7 Episode 13, "Tailgate", his father's grave reads as Marvin Eriksen. In Season 8 Episode 11, "The Final Page: Part 1", his Facebook name is spelled Marshall Erickson.
(at around 6 mins) After Barney has mouthed how his day was, Ted says that he didn't understand a word of what he says, then Robin says: "Sorry, buddy." Which could be misheard as her saying "Sorry, Barney" which if she had she would unjinx him.
The rules of "Jinx" are that only a person present can unjinx by saying the name. Why didn't Ted unjinx Marshall an Lily at the end? He was there and Barney had already released his jinx.