There was the interesting incident in 1961 when a Ms Berry pulled the cord, under circumstances which she believed to be reasonable and urgent (it was claimed that a man was molesting her, and a man was indeed prosecuted for "interfering with her comfort" and for "boarding a train while it was moving".) Nevertheless, she was also prosecuted by the British Transport Commission for pulling the cord, and fined.
She Appealled, won the Appeal, and was awarded costs against the Commission, but was still out of pocket as her costs had been higher than the award.
So, she then launched a prosecution against the Commission for the tort of 'malicious prosecution' and claiming damages, reported in Berry v British Transport Commission [1961] 1 QB 149. This would be a jury trial, for which she applied for, and was granted, legal aid.
That trial turned on a complex argument over 'damages' and although Diplock J couldn't agree that her loss fell under any of the established 'heads of damages', he did allow an appeal so that this point of law could be clarified, and which appeared to be unreasonable in the present circumstances.
But frustratingly, the Legal Aid Commission, who had been willing to fund her claim for 'malicious prosecution, then refused to fund the clarification of the law; Diplock J took this refusal to be a snub against the Court. Eventually, however, the Counsel who had brought her claim agreed to bear their own costs in the Appeal, and after lengthy argument, Devlin JL gave a lengthy analysis of the recovery of costs in civil and criminal proceedings and showed that there were injustices which should be addressed, agreeing that Ms Berry was entitled to recover her costs. Though in the end, the Commission settled out of court, paying her £850.
The fine for pulling the cord was, at that time, just one pound.