LTC4011:About the body diode of the external FET

Hi, I would like to use LTC4011.

So, I have a question. Please help me.

Question:

I am experimenting with the LTC4011.

I'm writing a circuit diagram first.
When checking the reference circuit, there is an unknown point.

The body diode is attached to the external FET,
This diode causes current to flow in the direction of the red arrow even when the adapter is connected.

Is this an error?
Or does it have any special meaning?

By the way, the body diode is attached in the same direction in similar products (LTC4008 / LTC4010) and these evaluation boards.

I think all of the above problems will occur.

Best regards,

Naohisa