It's possible. We don't have any DL320 servers, but my assumption would be that you have 2 NICs and they are integrated onto the system board. So, it's possible that the system board took a hit and fried both the network interface ports.
Did you experience anything new that may have contributed to this problem? Power spike, server down (off), etc.
Light travels faster than sound. That's why some people appear bright until you hear them speak.