WA sexual harassment and employment laws

Coworker shocked me: A coworker of mine shocked me with adult novelty item of a laser pointer/shocking device. I've had unexplained pain since than from my entire left side, after numerous tests I've been diagnosed with fibromyalgia. L&I hasn't accepted any claim yet and it's been almost 2 months. This accident happened while I was working, I have not been able to work since than. Some people say my coworker is at fault, some say my coworker and my employer. Do I have a case? Any suggestions? I was healthy and pain free before this.