There has been a mix of surprise and red top press gloating about yesterday's unanimous not guilty verdict for former News of the World editor and News International CEO Rebekah Brooks.

However in court itself, where observers had carefully followed the evidence, there was no astonishment when the jury gave its verdict. Indeed many had been saying for months that on the phone-hacking charges, there was very little evidence against Brooks. There was "no smoking gun", as her barrister said in his closing remarks. So what was the prosecution case?

Brooks, it should be remembered, was only editor of the now defunct News of the World from 2000 until early 2003 and the charges of the illegal interception of voicemails only ran to 2002. There was a very short window where Crown lawyers could link Brooks to hacking as there was no evidence it took place at the Sun when she became editor of the daily tabloid in January 2003.

Jonathan Laidlaw QC asked the jury to consider the fact that there were only 12 confirmed voicemail hacks while Brooks was editor and for none of them was there an email, a note or a witness that mentioned her name in connection with the practice. While convicted phone hacker Glenn Mulcaire was being paid under her editorship, the defence said, it was not the editor's job to micro-manage the budget. She gave departments spending limits and if they stuck to them it was not Brooks' role to inquire further.

It was understandable that the prosecution barristers made much of the fact that the hack of murdered teenager Milly Dowler happened in 2002, when Brooks was in charge of the paper. The defence countered that Brooks had been on holiday in Dubai with her then husband Ross Kemp when the "Milly voicemail" story appeared in the paper. Brooks agreed she had been in telephone contact with the acting editor Andy Coulson while she was away, but told the court she had been discussing front page story about actor Michael Greco leaving Eastenders and no one had discussed the Dowler article with her.

The prosecution case relied on the "editor's question" – the idea that Brooks would have been asking where every story came from. The former editor responded in the witness box that this did not reflect the reality of a modern newsroom. Journalists, she said, were "secretive" about their confidential sources and stories were checked by department heads and the in-house legal team at the paper before being published.

Brooks' role, she told the jury, was to oversee the whole process; not to "police" the experienced journalists and news editors who worked under her.

The same argument arose on another charge the defendant was acquitted of: bribing public officials. Email evidence showed that on 11 occasions while editing the Sun, Brooks approved payments for stories that were sourced from a Ministry of Defence civil servant, Bettina Jordan-Barber. However the defence contended that nowhere in the emails was the civil servant's name, or role, mentioned as she was only described by the reporter concerned as "my number one military contact". While the prosecution said that it would have been obvious from the stories concerned that this must be someone with inside information, the defence responded that a busy editor dealing with an experienced reporter could not be expected to assume the payments related to a corrupt official. One could argue, they said, that she should have asked but that alone was not proof that Brooks ever did. Legally, for Brooks to be guilty she had to know and agree that the cash was going to a civil servant. Not inquiring may be questionable but it was not a crime.

The final two charges against Rebekah Brooks were always seen by everyone in court as the weakest. The first related to her personal assistant removing boxes of documents from the News International archives. The PA, Cheryl Carter, told the court the boxes contained her documents and she had never told Brooks she had retrieved them on the day it was announced the News of the World was closed. The former editor's husband, Charlie Brooks, told the jury that he had hid items from the police who were about to search his flat but these contained his personal, and legal, pornography collection which had nothing to do with the hacking inquiry. At no point could the prosecution prove this was false, although they did raise the question of "missing" electronic devices which they said had never been recovered. The jury clearly were not convinced.

When you cover court cases you often find that not guilty verdicts are often given not because the jury think the defendant did not probably commit the crime; instead it is often the case that the jury have decided that the evidence presented to them does not meet the high standard required for a conviction. Recently the English courts dropped the phrase "beyond a reasonable doubt" on the grounds that it was too confusing and have replaced it with "if you are sure". Often juries will think someone is guilty on the balance of probabilities but decide they cannot be 100 per cent sure that the defence explanation of events is impossible.

Rebekah Brooks has been cleared by a jury after an eight month trial and leaves court without a stain on her character. However when you read the press headlines, especially the tabloid press ones, claiming that she has been declared "innocent" or has been "cleared", remember that no one ever knows what that jury really thought. All we can be sure of is that after listening to both sides of the argument, those 11 randomly selected people felt they could not be sure enough to convict and despite all the money spent on this marathon trial and all the legal talent deployed, that is the only fact that matters.