A 25 year old gang member presents to the emergency department with a 1cm laceration over the third and fourth metacarpophalangeal joint of his right hand. He is right handed. When you ask him how he got this injury, he says "Uh, well, um, I was working on my house, and uh, I got cut while painting. Yeah, painting." The exam shows tenderness, erythema, swelling, purulent drainage, lymphangitis, and low grade fever. Four separate isolates are cultured out of the wound, both aerobic and anaerobic bacteria.
Challenge: How did he get this wound?