It's not that terrible that you laughed at it wilky. You won't get special time in purgatory for it. It may seem crude, but so is laughing at someone who gets hurt and we all tend to laugh at things that we probably shouldn't.
There was a girl I knew years ago from Victoria that was willing to do anything I wanted after only knowing me for less than an hour. Yet when I asked if she knew a childhood friend of mine who moved to Victoria she called that girl a slut. That's not really funny, but yet it is.