I expect she reacted the same way I would have - shocked into saying too little, and thinking of all the good answers when it was too late.
Maybe we should write our own script and memorise it, ready for any similar situation, telling him exactly what breed of selfish, arrogant arsehole he is! Followed by telling him (even if it wasn't quite true) exactly WHY we needed to hold on to the handrail and the reason the handrail is there in the first place - not for him to drape himself artistically over, but so that older people could get a bit of help. Adding that if we didn't hold on, our disintegrating hip joints would be unable to support us climbing these steps and we would probably fall and knock him over as we gasp for breath because of our COPD, and cause someone to call an ambulance and the police, who would not find him amusing.
The other side is that the internet is full of little videos and "readers' stories" which tend to tell very simplistic tales where one person is the villain and the other is the victim. The villain/villainess is a boss/mother-in-law/landlord , who is trying to take the credit for the employee's work/gaslight a daughterinlaw/get a tenant unfairly evicted. That video may have been faked to raise outrage and get clicks to monetise someone's account.