The phrase "a one off error" is correct and usable in written English.
It can be used to describe a mistake that is not expected to happen again, indicating that it is an isolated incident.
Example: "The report contained a one off error that was quickly corrected in the final version."
Alternatives: "a one-time mistake" or "an isolated error".
Even if these hawks are eventually proved right, it will be hard to shrug off Mr Bush's remark as just a one-off error, or a slip-up by the CIA, as Mr Tenet has loyally been saying.
The leader of Kingston council, Derek Osbourne, told local media that he regarded the case as "a one-off error of judgement" by Chew and that "we have no concerns about her".
For what is considered a one-off error – and cases of mistaken identity remain rare – the favoured tactic is for the official to "get back on the horse" at the first opportunity.
(Not till thirty years later, in the mid-1990s, would he eventually get around to saying something more critical about Stalin than that he had been a "hard driver". And when he did apologize for his slavish, decades-long fealty to the Soviet line, he treated it as if it had been a one-off error in judgment, like John Edwards's vote for the Iraq war).
We can confirm that this was a one-off, genuine error.
That's no one-off error when official figures show more than 1,700 disabled people died last year within weeks of being found "fit for work".
On the one hand this single episode involving a firm with (at this point) just four buses could be dismissed as a one-off, a misguided error on their part, or just small fry.
Our quality controls include the exclusion of singleton alleles as possible sequencing or other one-off errors, a reassessment of the protein-coding status of the annotated genes undergoing a C-terminal extension, and the exclusion of one gene fusion event as a likely assembly error.
The ABS said the error was caused by a "mail-merging error" that was a one-off issue.
Andrew Tyrie, who chairs the committee, said: "The committee will, among many other things, examine whether these errors were a one-off or whether they reveal something amiss, perhaps seriously amiss, with the standards and culture of the FCA.
