"It is an unfortunate error, one that we regret."
It was all an unfortunate error and I, for one, find the company's explanation totally convincing.
"I'm sorry you were startled, but it was an unfortunate error."
"The tactically unfortunate error was not to work on an endowment during the years it might have been easy to do."
An unfortunate error which alters the balance of the game.
I left early every evening and shirked my duty- ultimately contributing to your unfortunate error.
An unfortunate error also resulted in seventeen questionnaires with the question deleted being issued on a week day.
This situation was not helped by both drivers making several unfortunate errors during the course of the season.
The court ruled the entire incident was an unfortunate error and acquitted both pilots.
Due to an unfortunate error in the language grammar, the implementation of ?