grave mistake

As is the case with most grave mistakes, this one was made by intelligent men, for the very best of reasons.

The supreme court made a grave mistake with this decision.

Although, now she came to think about it, maybe such caution had been a grave mistake.

A grave mistake, however much fun it had been at the time.

Love for anything other than oneself or one's child was a grave mistake.

If you ask me, putting those things around was a grave mistake.

How could the police have made such a grave mistake and failed to cut off his retreat?

Had it been a grave mistake that brought him to this place?

And surely it's a grave mistake to bring him here.

That is why I regard this as a grave mistake.