This issue will be covered in the release note, you should be able to get it from the portal soon, and yes, you can reference it to this case when you open new ticket for FW upgrade later.
For your second question, there is no proven evidence that LSI FW would cause the node to hang, but we have seen a couple of rare cases that G4 lockup happened on nodes after the BIOS / BMC upgrade, hence recommend customers to upgrade LSI FW to latest to isolate controller related error.