Elsewhere I read the pump actually did have an entrapment system engaged and shut off, but by the time she blocked the pipe and sensors detected the obstruction, she was already wedged 20 feet into the pipe.

In other words, if this had a simple grate and she blocked it with her body, the pump would’ve shut off almost immediately.

The other problem is this hole was supposed to be an outlet, not an inlet. But the pump was reversed for whatever reason.