Thanks for getting it =)
Sardines ARE hard to come back from. That salty taste is gonna stick with you for a while.
You make a good point about how people view sick humor.  
Not to go all in and say ALL humor is appropriate since there's no such thing as an attitude that is *always* correct, but I think humor is an apt reaction for situations where there is just no easy way to talk about it, or no clean stance to have on it.