I can’t read minds, but IIRC, Spaide had already called the cops on the couple before over something. Maybe the wife began filming, thinking that she’d bait him into committing a crime like menacing, assault, or something like that as a way of getting even with Spaide. Or maybe I’m just over-thinking all this.
Anger and fear speed up a person’s mind and their reactions. They block out rational thoughts; they make us operate on instincts, and instincts are often incompatible with analyzing the long-term consequences of our actions, which is ultimately what I think happened.
I think Spaide became so enraged that he just literally snapped. He had probably mentally played out some of what happened in his mind, either because he really feared for his safety, or perhaps because he had so much contempt built up toward the couple (which seems mutual, btw) that he began fantasizing about removing this ‘problem’ from his life forever.
I think some of us reading this have experienced dealing with someone we loathe. Maybe it’s a bitter dispute with a family an estranged family member, or a neighbor, or a boss, or a co-worker. What makes it worse is knowing that you can’t just escape the situation. You and your nemesis will inevitably confront each other again. The mere sight of that person or those people triggers a response, and the response tends to intensify over time, with each new encounter.
Spaide was already pissed at the mere sight of the Goys – and then of course, they amplified those already intense feelings with their behavior. We don’t have the full story, but I don’t know if you need it when it’s clear that the Goys are the ones who walked across the street toward Spaide. That fact is telling, to me, as is the fact that Mr Goy threatens physical violence and repeatedly calls him a pussy, with his wife egging him on in pretty much the same bitterly confrontational tone. It’s clear who the aggressors are, in my mind. It’s entirely possible that if we interviewed various neighbors, friends, and family members with a more complete knowledge of the situation that we’d find some instances in which Spaide may have escalated the situation or could have handled some things differently. But in this final episode, it’s clear who the aggressors are.
So someone who’s already mentally on high alert sees a pretty big guy and a companion walking toward him, behaving aggressively and speaking loudly and aggressively. In nature, when male primates, from which we evolved, show dominance, they throw large stones and shake trees. This is basically what Goy was doing at this point. He was showing Spaide, someone who was already triggered and already prepared for lethal combat, that he was capable of violence.
At that moment, Spaide’s switch gets flipped to the ‘on’ position. Adrenaline and emotions begin to flood his brain. He can no longer think rationally. Spaide’s brain, doing what it was engineered to do over millions of years of human evolution, scanned his environment for threats, and then simplified his decision making mechanisms so that he didn’t have to put much thinking or analysis into what he was about to do next. Like our more primitive ancestors: he saw danger in front of him; he neutralized the danger.
After a few moments, he realizes what he’s done. He reckons with the fact that whereas 15 minutes before he was just Jeff Spaide - veteran, citizen, uncle, and neighbor - he was now Jeff Spaide, double murderer, who would at minimum face the rest of his life in a very dangerous prison environment. That was something he wasn’t prepared to face, and frankly, a life he felt he didn’t deserve. So he checked out.