Oh, I'm so sorry to hear that about your dog! I'm glad he's going to be okay. Our whippet puppy is named Mylo as well.
I just talked to my British half and he told me that what the dog owner did is against the law. Here is a link to the government website about leash laws:
https://www.gov.uk/control-dog-public/overviewIf you don't want to click through:
Overview
It’s against the law to let a dog be dangerously out of control anywhere, eg:
-in a public place
-in a private place (eg a neighbour’s house or garden)
-in the owner’s home
The law applies to all dogs.
Some types of dogs are banned. ** my addition: this include the Bully breeds
Out of control
Your dog is considered dangerously out of control if it:
-injures someone
-makes someone worried that it might injure them
A court could also decide that your dog is dangerously out of control if:
-it injures someone’s animal
-the owner of the animal thinks they could be injured if they tried to stop your dog attacking their animal
I would definitely talk to the neighbor about your how your dog is doing, feel her out. My husband said if he was you he'd make her feel a uncomfortable, bringing up the above law. The fact that it took 3 workmen to get the dog off yours... It's definitely not a good thing.
You could take them to small claims court, it just depends on how you feel about possibly ruining your relationship with your neighbor.