I would say neither party comes out looking great. They do come across like entitled twats (to quote Itchy) and yet the police response seems OTT. Surely they could have taken names and registrations and issued a warning that they'd be fined if they were caught doing it again?
The hot drink constituting a picnic also seems ridiculous. But on the other hand, they've both left their houses by car, presumably gone through a Starbucks drive through somewhere and then driven to the Reservoir. Is that an essential journey? I appreciate the immediate surroundings of home may not be as pleasant a walk, but why not make a coffee at home and walk from there? One of the women states she has anxiety, so getting out of the house for a walk is obviously important for her mental health, but not sure I buy the excuse that walking by the water is more effective.
On the police, why were there so many there? It would only take one car to turn people away and fine them if necessary.