I guess the oddest neighbor thing I've experienced happened when I was 10 years old. We lived in a tiny town deep in the old South, where everyone knew everyone, a visit to the library and post office happened on the same blck, etc. I unfortunately did not witness this, but one day as my parents and brother stood on our porch, a bloodied man limped/ran down our street, yelling and glancing behind him. Seconds after, a woman ran/limped down the street after him, yelling and waving a really big knife.
They called the po-lice, but never heard what went on. Domestic violence was pretty common in our area, though.