While the friendship that does survive a fight is strong verification of a true friendship, the absence of never having had a fight does not mean it is not a true friendship. So while it is possible for a true friendship to exist without a fight. It will take other means to prove it is a true friendship. I think a more accurate statement would be to say: "A friendship that does not survive a fight never was a true friendship." But that does not mean a true friendship has to have had a fight.