Planchet flaw

[koincollector]

Hello,

 

Can you tell me why coins with a planchet flaw get body-bagged even though the defect is present on the coin even before it leaves it?

 

I have seen coins in NGC slabs which have been lacquered by the mint and in an earlier question was told they were acceptable while post mint lacquering was not. So why is mint made planchet flaw not acceptable?

 

Second unrelated part of the question-- does NGC body-bag even the early period hammered coins (world) which were stuck with planchet flaws and all (majority of the examples were stuck like this)?

 

Thanks!