Indeed, I was surprised to read that too. Probably mistake on author's part.

This 1996 failure was not a "production" flight but a "test" flight (the very first test flight in fact). I guess the article implicitly claims all "production" flights were flawless.

But that too would be an overstatement. There was a second (and last) failure in 2002 for the first test of the ECA configuration of Ariane 5. (ECA, Évolution Cryotechnique type A, is an improved Vulcain 2 first-stage engine with a longer nozzle with a more efficient flow cycle and denser propellant ratio.)

All ~75 launches since 2002 have been flawless.