This was without doubt politically motivated harrassment by the police, with the victim being arrested and locked up for 7 hours. She was released and charged with Section 5 of the Public Order Act and bailed out of the county of Sussex. Not just Crawley, the whole of Sussex!
Of course Crawley is such a pleasant, polite town. In recent local elections 12% of those who voted chose the BNP. But obviously swearing is a much bigger and more important issue than wanting to deport innocent people back to countries where they may face rape, torture and murder.
It is however no coincidence that the people who were harrassed were on there way to the day of action against racist immigration controls. The police didn't seem offended when fascists stirred up racist hatred shouting at those at the demo.
Although the whole incident was highly amusing at the time, it's getting less and less funny how political activists are being increasingly targeted by such police tactics. Unfortunately for them this kind of behaviour only serves to make us more angry and motivated to fight back against this oppressive system.
No borders, no swearing
(a) plead NG - unless they can prove that someone was within sight or earshot who was likely to be harrassed, alarmed or distressed, they lose. However, the coppers will no doubt attest (aka lie through their teeth) that young children were nearby and could have heard...and courts like to take coppers' word for it. However the fact you mumbled (half-coughed) the word makes it even less likely anyone heard it except FIT, and FIT officers almost certainly do not (should not) count as people likely to feel alarmed by you.
(b) admit doing it (i.e. saying the word in question) but ask the Prosecutor for a Bind Over to keep the peace. It is not a formal conviction and therefore won't show up on your record. Accepting a bindover (i.e. a promise to be good as gold for the next X months) is at the Prosecutor's discretion, so just ask them nicely and they are likely to go for it for something as silly as this. You could always go the whole hog and ask the Prosecutor (independant of the police) to drop the charges...