The scriptSig could include the CHECKSIG opcode directly, contra standardness rules. 
In the original idea, a p2sh redeemscript is just pushes, so the spk could just be blank and it would pass, since cleanstack isn’t consensus anyways.
The scriptSig could include the CHECKSIG opcode directly, contra standardness rules.
In the original idea, a p2sh redeemscript is just pushes, so the spk could just be blank and it would pass, since cleanstack isn’t consensus anyways.