POSTSAVER^® USA recommends that posts and poles should not be installed if the boots or sleeves are punctured. 

In the unlikely event that a boot or sleeve would become damaged, the bitumen under-layer does provide an effective secondary sealant that protects the wood from decay.   Note that independent tests indicate a very substantial increase in post life even with 25% of the boot cut away.

Repairing a boot or sleeve is very simple.  Simply apply a self-adhering rubber roof sealing tape such as Mule-Hide Seal-Fast^® or equivalent over the punctured area.  It’s that easy!