to have done something which is wrong, for which you should be blamed.
If they failed to notice the damage, they're definitely in the wrong.I fully accept that I was in the wrong and I think I ought to apologize.
be in the wrong
To have done something incorrect or inappropriate. The other driver was totally in the wrong—he hit me, after all!I was in the wrong to assume that you two had reconciled. I should have checked before inviting you both to the dinner party.