@Cranberry.
According to the Leveson enquiry, the police revealed that there was a high probability that texts messages had been deleted by the NOTW investigators. However, the message deletion that gave the family hope that Milly Dowler was still alive, was more likely than not an automatic system deletion. The fact that it was the NOTW listening to said messages that may have trigged the auto-deletion is also a possibility.
There is a difference from inaccurate reporting based on facts not available at the time of printing a story, partly due to the bang up job the police were doing at the time and not releasing the phone log information until compelled by the Leveson inquiry, and writing a wilfully misleading article.