There is an existing thread on what the process is to get IP addresses removed from the reputation list, so I'm not going to rehash all that here.
I believe the IP reputation page does display the reason for the IPs status.
Keep in mind that this is just a public forum, it is NOT a customer support portal, so posting a request here to get something delisted isn't going to be productive. The best path forward is to open a case with Customer Support. If you are NOT a customer, then the best path forward is for you to find a customer common to both BRCM and yourself to open a case to get the IP in question removed.