I don't know.... The Florida code is: 2 main drains per pump. Meaning you can't just have one. 2 MD 3' apart on or different planes for anti-entrapment. I'm not sure it says anything about not having any main drains. I'll have to check. And I don't know why anyone would want to fight it anyway.

BTW similar accidents happen with vacuum cleaning lines if a spring loaded cover is not installed.