Why are you concerned?

Everyone knows its a tough song and under pressure people (who have probably sang it a 1000 times) make mistakes.

Concerned just seems like a very strong word. People will have opinions one way or the other about performances and that's the nature of the beast. I don't think anyone on this board has ever had a perfect performance. Every musician in the world has messed up lyrics----to their own songs!

If your statement is about patriotism and the such, then I think there are far bigger issues than knowing the words to the SSB.