Hiya from Leicestershire
If you read back through some of my previous posts, I have a had a long road with separation anxiety with my Teddy.
Firstly, no matter WHO tells you it's a good idea to let your dog off the leash and as you have experienced yourself, it is NOT a good idea. It is NOT cruel. What is CRUEL is pretending that cars do not smash dogs and other dogs do not kill dogs because what we WANT to be reality is not the case. That is cruel. I had a trainer who told me to let my dog off and it worked, for a time, but his terrier instinct kicked in and he ran towards traffic (ignoring recall commands which he had previously listened to) because he saw another dog and followed it even when it was out of sight. Had it not been for a very strong set of legs (not mine), my dog would have been dead and how could I blame traffic? I would have no one to blame but myself. Therefore, my dog is never let off leash just like my cat is never let out of the house. I committed to their safety and someone else's opinion does not even factor into my decisions re: these points!
As far as separation anxiety, I empathize with you so completely. It was at 8 months where I had to call someone in for some 'professional advice' re: Teddy and his behavior. The guy was a total moron so did not help me at all. Therefore, I will not be sharing any of his 'advice' here. HOWEVER, my situation is different because I do not have the pressure of neighbors (my house is detached). If I had, I wouldn't have had a dog in the first place.
Therefore, like gemy has suggested, I would recommend you find a trainer as you may be doing something to reinforce anxiety and not even be aware!!! I found that I was doing a few things (like allowing the dog to follow me throughout the house, for example) which reinforces his belief that he needs to know where I am at all times. However, when I command him to STAY so I can leave a room and come back (and then reward him for STAYING upon my return), I am showing him that just because I'm gone - doesn't mean I've disappeared forever! Small things like this CAN HELP.
Teddy, however, still barks and is very anxious. I have consulted vet opinion etc and if you want more details pm me or I can refer you to a couple of threads I've started re: these.
I think your first port of call is to establish if your dog actually suffers from anxiety or if there are some training issues and then go from there. Then, you can argue with the HA that you are being very pro-active in trying to rectify the problem and can show evidence that you are at least working on it, you know?
Good luck xxxxxxxxxx