She supposed to be a highly rated, high ranking lawyer herself. Says a lot her her confidence in her own good judgement if she's engaged another lawyers to speak on her behalf.
Lawyers have a saying: "Any lawyer who defends himself has a fool for a client."
Meaning that to defend someone requires rational, level headed, tactically astute thinking - something you are unlikely achieve if you are personally involved in a case.
Another point is this lass is commercial lawyer, what she knows about the criminal law could be written on the back of a postage stamp.
Wisely, she recognised both of those limitations and engaged someone who, presumably, does know what they are doing.
This being the internet, lots of people will sneer at her because she's loaded, and suggest she has escaped prosecution due to that wealth.
However, the only relevant question is: "A dog running free attacked a seal, has the owner committed a criminal offence?"
The Met and RSPCA decided the answer is 'no'.
For what it's worth, I can't see what offence she committed.
The dog is a legal breed and seals have no protection as a species in these circumstances.