'He immediately snapped, “I told you no,” in a raised voice and basically kicked me back out': Worker in shared office refuses to let coworker in to retrieve their bag, lashes out at them

Sharing a space is not always easy. You know this if you've ever had a roommate. Maybe in your freshman year of college, you shared a room with someone you didn't know. You had to learn how to be respectful of each other's space. You learn not to be loud at night or turn the lights on when they're sleeping. You shift your habits to keep the peace. It might not be fun, but it beats a hostile roommate situation. Then you carry these skills into adult life, and they will serve you well. Maybe you end up with roommates as an adult. Maybe you move in with your significant other and have to negotiate that. Or maybe you end up with an office mate. 

It's important to keep up those rules of kindness and not sabotage your shared spaces. Even if it means making some compromises now and then, it's worth it in the long run. But not everybody internalizes these rules, and that can sometimes lead to major conflict. Like in this situation, where an office worker didn't know how to share the space with his coworker.