I wasn't talking about little offenses like bumping into someone. I was talking about things like making insensitive remarks or unfairly directing negative feel

I wasn't talking about little offenses like bumping into someone. I was talking about things like making insensitive remarks or unfairly directing negative feelings or anger at someone who doesn't deserve it or wasn't the cause of the original stress factor that led to the anger. Or maybe even worse things than that. Generally, things about which a person might come to feel some kind of deeper remorse. I do think it's often possible to identify the first person who lost their cool or decided to project their own internal conflict onto someone else. This can sometimes turn out to be oneself.