We have never had a problem with the owners dog but on any site we never leave the dog outside unless we are with her

Our elderly dog spends most of her time outside. The owners dog/s don't come anywhere near.

Well Mr Cutting, this is a very unfair review. 
you only booked for one night, and so that hardly gives you enough time for a very balanced review of the CL. The fact you left your dog tied to a fence probably says it all. 
It is.a perfect CL for dog lovers and walkers, and if my own dog occasionally escapes from me onto the site, he is nothing but friendly, unless of course your dog had a go at him! Which I think is the case. 
There are always 2 sides to every story. 

I would also say this was a very unfair review, we didn't have any problem with the owners dog, it seemed quite friendly - perhaps yours being tied up was apprehensive when the other dog came along and it's hackles went up when the site dog was wandering by. 

Anyway, so sorry to hear of your problem, we keep our dogs either in the caravan or awning unless we are sitting outside, when we would have them tied up close to us. Having then moved on from Penny's CL to a CCC club site in Canterbury (I'm a member of both main clubs) we saw a large rather boisterous labrador escape from the owners awning and then decide not to be caught.....fortunately early morning, so with the help of the wardens it was rounded up. That could have been a different situation if it had come across another dog tied up. These things occasionally happen and it's easy to be wise after the situation on how as a dog owner you can avoid confrontation when one dog is either tied up or on a lead and the other is not. Anyway enjoy your camping elsewhere and leave this site for others to enjoy if you don't like it :-)