The use of quotation marks is grammatically and journalistically correct. An impartial news organization should not report the accusations of third parties as

The use of quotation marks is grammatically and journalistically correct. An impartial news organization should not report the accusations of third parties as fact; it should present them for what they are. You will see the same thing in coverage of court trials. Prosecutors are wont to make many bold accusations, many of which will be found to be false or unsubstantiated. It is imperative that journalists present these as mere accusations, and quotation marks are an effective way of doing so.