It's actually a rental so we can't touch the current fence. We're going to build a separate fence around the back door but we haven't had a day off to do so yet (we only got him last week). It'll get done tomorrow, my boyfriend's first day off.
To be clear, because I might have been unclear before, he didn't bite her but he did catch the buckle of her shoe after she stopped biking to scream at me. And I didn't expect sympathy from her, exactly, although she could have been much calmer and less aggressive herself. The reason I included her response is to highlight how dangerous a situation it was for us. There was nothing stopping her from calling the police or animal control. I want to be clear that I'm taking this very very seriously.
Also, she literally was screaming at me, telling me he was a terrible dog, that I needed to show dominance, that I clearly had no leadership ability, etc, etc even after I had him under control, holding him tightly in my arms, which obviously had an effect on me. This is one of the few times in my life someone has screamed at me, and I don't raise my voice myself, so it was out of my comfort zone and I didn't know how to productively react. That obviously affected my judgment in putting him in his crate during a negative moment... now I'm no longer crying, I'm kicking myself because I don't want it to be a tool for punishment.
How do you suggest we work on leash reactivity? The only advice I see online is using treats and, again, he is not food motivated. He turns his nose up at almost all of the food/treats we've tried with him. We're also still working on sit/stay with him in the house, trying to use his toy as a reward (if he sits when told, we throw it... its going slow). I do feel he's been getting better just by virtue of keeping him on a short leash, his harness, and not stopping when he kicks up a fuss but breezing past whatever is triggering him. I want to take him to training lessons but I'm scared he'll be too violent and it'll end in tears again. We're seeing a vet tomorrow so I'll mention this all to her as well