The spec in a large number of cases specifies the required action in the case of detecting an error. However, it is quite possible that a server or client can detect multiple errors in the same packet. The return code and indeed the action to take (return an ACK, close the connection) might be different depending on which error the receiver of the packet detects.
I propose a statement that in the case of multiple errors in a packet, the receiver is free to report any one of them and take the appropriate action. I would prefer this to be in normative text