[SpamCop-List] Still trying to understand frequent 'report already sent'

[Possum Trot]

Deputies,

I carefully watched what I sent today and still had several "report already 
sent" indications.  Could it possibly be because one of the many who were 
CCd on these same spams had already reported it?  I know there was no 
possibility I double submitted 3 or 4 of the spam that got that message 
today.