LM5017EVAL: Why Diode is used between Vout1 and Vcc pin?

Hello All,

I am going through this document  https://www.ti.com/lit/pdf/snva611. 

Vout1 is 10V and Vcc is regulated at 7.6V(as per datasheet) so Diode(D2) will be always in forward bias then why here you have used Diode (D2) ?