How can this locked SS be opened?

A friend is new to , created a ss in Numbers 3.53 then Quit. When

he went to reopen the doc Numbers demands a password even though

he didn't knowingly lock the doc or set one. Ironically, the ss was a

compilation of his accounts and passwords. He's really upset - is

there a way? As here, Keychain Access doesn't have a Numbers pw either.

In addition this comes up when he tries to open Numbers.

Permissions have been repaired.