If the ScriptSig provides a public key that does not hash160 to the 20-byte hash in the ScriptPubKey, the script will fail at OP_EQUALVERIFY
If the ScriptSig has a public key that hash160s to the 20-byte hash in the ScriptPubKey, but has an invalid signature. That would end the combined script evaluation with a 0, ending in failure.
If the ScriptSig provides a public key that does not hash160 to the 20-byte hash in the ScriptPubKey, the script will fail at OP_EQUALVERIFY
If the ScriptSig has a public key that hash160s to the 20-byte hash in the ScriptPubKey, but has an invalid signature. That would end the combined script evaluation with a 0, ending in failure.