Attorney did not appear

A hearing was scheduled for a contempt charge, but the opposing attorney did not appear. My mother’s lawyer simply stated that the hearing would not take place because the opposing attorney “could not be there”. What the ???

What reasons would the court excuse an attorney because he “could not be there”?
Or did the court excuse him?

What should have happened? Thanks.

The attorney may have had another case in a higher court, or some other valid reason requiring the court to excuse the absence.