We used to call it a "nervous giggle" a long time ago. A stressful or embarrassing situation can cause that common and normal response (someone in pain or someone aggressively angry is very stressful).

I do not think you are a sociopath because of a tendency to giggle in very *not* funny situations (some people freeze or faint or sneeze or hiccup... the danger danger signals send the body chemistry into overdrive.

Do you find their sorrow or pain actually funny and then giggle? (like a sociopath) or
Do you respond to observing their sorrow or pain as *not* funny but the stress causes a giggle? (like a nonsocipath who does not want to see anyone in sorrow or pain or rage)

I am sarcastic humor type in normal situations and my flaw gets much worse in stressful situations (um... yes, I have difficulty with "appropriate response".... I have been informed my critical comments and sarcastic glee are not appropriate at times)

The guy slipping on a banana peel is classic slapstick humor that still makes most people giggle (it "becomes" not funny later when he lays there injured on the banana peel). Other people develop a cold morgue humor to handle the stress of grief, loss, crime, death, etc.

You are okay and nothing is wrong with you. Now we can both giggle and ***not*** feel guilty later.