This is precisely what Griffin would have wanted, and expected to happen. It's unlikely he'd have bothered to pursue sucha trivial prosecution if he actually thought he would win.
The BNP's main tactic is victimhood. They target people who feel marginalised and ignored. To appeal to these people, they BNP sets its self up as the party that the other paries try to ignore and marginalise. One of their standard refrains is that the authorities don't listen and don't care about what is happening to everyday
Of course, the authorities, both locally and nationally, are adhering to their accustomed policy of studied denial about the scale and prevalence of anti-white racist attacks. (2)Winning his case would have shown that the BNP could be treated fairly by the system.
Griffin has lost his case, but I doubt he'll be at all upset about it - the BNP has gained another example of supposed politically correct racism against whites. He gets some publicity, and, much more importantly, gets to bang the "PC Authorities Ignore Racism Against Whites" drum a bit.
1 - "Man cleared of BNP racial abuse," unattributed BC article, published 4th of November, 2009. (http://news.bbc.co.uk/2/hi/uk_news/england/lancashire/8342591.stm)
2 - "Is Savile Town Becoming Yet Another ‘No-Go Area’ for British People," by George Fanning. Publsihed on the BNP website, 1st of November, 2009. (http://bnp.org.uk/2009/11/is-savile-town-becoming-yet-another-no-go-area-for-british-people/)