Everything in your body is a "chemical reaction". Pulling the trigger of a gun is a lot of chemical reactions. That doesn't mean the person isn't guilty.
In fact, it's problematic when people start thinking of their emotions as a chemical process that happens to them, outside of their control. A large part of getting people back on track in therapy is getting them to accept that they do have some control over how they react to situations in the world.
A lot of TikTok or Reddit style therapyspeak does the opposite: It goes to extreme lengths to try to separate the emotions or negative responses from the person, as if they're an outside force victimizing them. It's comforting to think that, because things that happen to us outside of our control seem like they can't be changed. Getting people to acknowledge that they can and should exert some emotional control over themselves is part of breaking that cycle.