Great! So glad things are going well for you both
That's good you found a class where you can work on his behaviour. Setting them up for success I think is one of the most imprortant things with a reactive dog.. Eventually you find they haven't practised the behaviour for so long, that being good almost becomes a new habit!
Keep the updates coming, even if people don't post we all love reading success stories

Well done! Sounds like you are doing all the right things, and that recall you mention is really impressive!

You mentioned in your original post that you feel bad - DON'T We all have to learn how to best keep our dogs safe and manage their quirks

Well done Helen for seeking help and taking advice - we all hate it when our dogs don't behave the way they should I am sure there isn't a dog owner out there who hasn't been surprised at their own dog's behaviour once in a while
It's great that things are starting to come together for you and Zac.
Good luck and keep the updates coming.