A question about "cross over" here:
"We all joke about the ways that we could maliciously behave in our jobs," Goldman said. "That's gallows humor. Going online gets problematic. With (Hodges) it was not just a joke, it was a running theme. At some point it crosses over from being a joke to a warning sign."
According to dictionaries, "cross over" could either a musician changing from one genre to another, or a person switching allegiance from one political party to another.
But neither definition applies to the usage in the example. Could it be an error?