Use 'back out' to describe someone breaking a promise or commitment.

Commitment Issues

'Back out' often implies a change of mind occurred unexpectedly or late in the process.

Last Minute Change

The phrase can carry a negative tone, suggesting unreliability or indecision.

Used literally for physical movement, such as navigating a car.

When used physically, it implies that extra caution or care is needed.

'Back out' can mean undoing changes in a tech context when problems arise.

In computing, it refers to reversing actions when managing versions of files.