When is a "mistake" almost right and nearly acceptable?!

       In an obituary today in the Los Angeles Times for the wonderful performance artist Rachel Rosenthal, the article tells us Rachel graduated from the High School of Music and Art in New York City and began to be friends with painters like Robert Rauschenberg and Jasper Johns and joined the dance company headed by Merce Cunningham:


           "She was a dancer and fell in with an avant garde crowd at a time             of artistic fervent in the 1950s."


       Now a spell-check wouldn't catch the "fervent" as a mistake or misspelling because it's actually a word, and although it is an adjective when a noun is called for and "ferment" was no doubt intended, a churning, boiling time of artistic creativity is also clearly one where the artists are "fervent" about their art!