Let me give you an example when I think the line is crossed. I am not much into soccer but I saw that soccer fans at the last world cup were using some sort of Zulu trumpet (Very similar in length at the trumpet we see in the statues of Moroni at the temple) well, some people were posting pics online of soccer fans with those trumpets and added the pic of Moroni in the crowd. I didn't think it was funny.
JB,
Sometimes people attempt humor, and they are just awkward / not very good at it. Maybe they even use words that would normally be considered disrespectful. I think I can "Usually" Tell when humor was attempted innocently vs when it contains a deliberate spirit of mockery.
So, how about when there is an element of mockery involved?