An act can be reversible for the decision maker and irreversible for the person affected.

The person deciding can often undo their decision, and the person affected frequently cannot. A policy can be rolled back next quarter while the months someone spent unemployed remain spent; a comment can be retracted while the thing it started continues. Reversibility is measured from where you stand.

Before making a decision that lands on someone else, ask what is undoable for them rather than for you. If the answer is that they cannot recover the cost, that is a reason for more care, more warning, and more consultation, even when your own exposure is small. Asymmetry of risk is the thing to look for.