I cracked jokes and made people laugh at my Dad's funeral. 5 years later, I still miss him and think about him all the time. Gallows humor is how I deal with a grief. This minister may be like that too. At my funeral, I want people to tell funny stories about me as they play "Another one bites the dust" by Queen.
"Death by a thousand cold cuts" was clever. I can understand why some people would be upset, but people should realize that not everyone reacts to bad news the same way. People shouldn't tell other people how to grieve or make judgements based on what appears to be callousness and insensitivity on the surface. Very likely this minister felt bad for the families and possibly responsible.
I have a problem if he tries to cover something up, minimizes the problem, fails to take action or blames someone else... Then his joke is not funny. But if he makes changes to the system to ensure this doesn't happen again or that the reaction time is faster next time around, then he's done his job and his joke was hilarious.
More Gallows Humor:
Know how to make a cat go "WOOF!"?
Gasoline and a match
Know how to make a dog go "NeeOW"?
Put dog in the freezer until frozen and then cut with band saw.
A man with no arms and legs, hanging on the wall is called "Art"
A women with one leg longer that the other is called "Eileen"
They are all here:
http://www.popculturemadness.com/Trivia/
Callousness and insensitivity depends on intent and motivation. If the minister didn't care that people suffered and died, his joke would not be funny. But I doubt that's the case here. Therefore the minister's joke was dark humor and may be his coping mechanism.
This story on the other hand describes people behaving callously. What makes their actions callous and insensitive is their indifference and lack of empathy.
http://www.guardian.co.uk/world/2004/nov/29/israel