Reading the BIP:
I see that the scriptPubKey in a transaction that funds a segwit redemption is the same as a normal P2PKH but merely prepended with
Is this opcode what tells older clients that the Tx is "anyone can spend" meaning that there will be no signature data in the redemption Tx?
Of course upgraded nodes will know to look for the actual scriptSig in the witness data to verify the Tx. But how does this
OP_0 fool old nodes into ignoring the scriptSig on the redemption Tx?