This is the key part that makes it The Onion material:

From, https://www.theguardian.com/us-news/2025/feb/17/miami-shooting-israeli-men

…one of the injured men reportedly posted “death to the Arabs” in a message on social media after the shooting. “My father and I went through a murder attempt against antisemitic background,” he wrote.

Jewish man shoots at Israelis because he thought that they were Palestinians. Israeli victims claimed that they were victims of an “antisemitic” attack and post “death to the Arabs”.

The deeper irony is that these men were the victims of an antisemitic attack. They were targeted because they were thought to be Palestinians who are also a Semitic people and yet they seem to share the same prejudice as their attacker.

It is a joke, it far overestimates the number of trained individuals…