Knee Slapnea

The most invigorating form of exhaustion known to clothed humans. In this condition breathing is interrupted for 15-30 seconds when laughing uncontrollably. Untreated, it may lead to spontaneous flatulence and staining of undergarments.

I feel terrible, I told Bob a joke and he fell down, rolling around in a fit of Knee Slapnea, am I responsible for any injury?