nieomylny Englisch:

He can always rely on his unerring intuition.

You have an unerring nose for malfeasance

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.