Not really, just another example of why punctuation matters. He was not laughing about what happened, or that it happened in San Francisco, he was laughing at the idea of the criminal receiving a harsh punishment, because the crime occurred in San Francisco. (Which would have been more accurately conveyed by saying “lmao, this happened in San Fran”)
That said, it is horrible that this happened, and I hope Pearsall is able to fully recover, mentally and physically, from this traumatic experience.