Thugs have no authority. The are responsible for the crimes they commit and should be jailed immediately.
...unless they have guns and governmental backing. In this case, they're more properly classified as goons. :(
Usually, the best way to deal with a goon is by one of two methods, depending on governmental status:
1) publicity and shaming of their superiors. You do it hard and heavy enough to generate outrage, and force change to a positive direction (change in policies, fire the SOBs who performed the violations, etc.) When appropriate, a loud and messy lawsuit can provide the same results, and simultaneously enrich you a bit for your time and trouble.
2) subterfuge and quiet resistance. In the case when a government has begun its descent into fascism, your best bet is hide what you must hide, find workarounds to the obstacles, and quietly help remove the fascist elements of the government. As an addendum, carefully probe the possibility of bribery and other methods.
Sadly, we're fast becoming forced to go with #2 - in most of the EU and in the US. In the above case, I suggest that the lady in this story continue to scream bloody murder, and perhaps launch a lawsuit for any credible reason (she's a lawyer, it wouldn't be hard for her to figure out some reason) but meanwhile use the Chunnel next time, and then leave/arrive from a French (or possibly Spanish or German) airport.
*sigh*... if only the population at large would get their eyeballs off the TV and celebrity gossip for long enough to realize just how far down the shitter we're all heading...
"but meanwhile use the Chunnel next time, and then leave/arrive from a French (or possibly Spanish or German) airport."
The UK still does border controls on those arriving from European locations.