infallible Anglais:

No work plan is infallible and changes may be necessary.

My instincts are good, but they're not infallible.

\(ˌ)in-ˈfa-lə-bəl\ - With this in mind and when you’re relatively new to UX design, you’ll certainly make some mistakes – nobody is infallible and some projects are just incredibly complex.

A seemingly infallible system that finally provides security.

Even the experts are not infallible.

He believes himself to be infallible.