nostr:npub1pm5z0gmw3wcvl3yreuv8y7q3stz2zmzc4jar4ckhk927qdcwjwuq3txe07 you have a confusion between ln protocol which is using on-chain rules settlement to act and Bitcoin who verifies the transaction.
Bitcoin is absolutely not penalize cheating. The protocol is built such that if such transactions are relayed the protocol act.
It’s exactly like enforcing an enveloppe into bitcoin and trigger the enforcement when Bitcoin tx is validated. And so you can say that Bitcoin validates the protocol as long as it validates the txs