Dog Attack on Green Lanes

I wasn't quite sure of the correct forum to post this message but this morning I witnessed a dog attack whilst driving along Green Lanes. It took place outside of Taksim Restaurant, near to Costa Coffee.

The attacking dog was a large mixed breed, mostly white in colour with light brown markings. The dog was off lead.

It's owner was tall, slim built black male, with shortish dreadlocks tied in a high ponytail. he was wearing a dark blue parka type jacket.

The dog that got attacked was a small brown dog and was being walked by it's owner (on lead) heading southbound towards Finsbury Park.

As far as I could see, the owner of the small dog was able to pick his dog off of the ground although this didn't stop the attacking dog from still trying to get at the small dog. The attacking dog's owner seemed quite nonchalant about the situation.

Sorry if this sounds a bit jumbled. It all happened so quickly and I was driving at the time. The reason I am posting this is to warn dog owners of this event and to be vigilant.

I would also like some advice on whether it is worth me reporting this to any authority?

If the owner of the small dog that was attacked is reading this, I did turn round and drive back to try and find you to make sure you and your dog were ok, but by the time I got back to the same location, I couldn't find you. I really hope you're dog is ok? It must have been a very traumatic situation for you both. 

Please can I ask that people keep their dogs on leads whilst walking on busy streets? As a dog owner myself, it can be really unnerving to have an off lead dog approach. And it is always a concern that they might be volatile.

Thank you.