your semantics are about the deposit and withdrawal. not LN itself
Wrong, individual Lightning payments are validated by Bitcoin nodes, as Bitcoin transactions. Each and every one.
the guy made a payment ON BITCOIN(deposit). and the separately used the LN node for payments.
the payments within the LN node are NOT accepted by bitcoin. go watch the video
only the settlement (withdrawal) is accepted because a process is done to create a bitcoin transaction when the channel closes.
No, all Lightning payments are validated by Bitcoin nodes. They're validated in the mempool. Not on the Blockchain. Until the channel closes, when the net result of the transaction is stored on the Blockchain. Not as an altcoin, as you falsely claim. Stored as Bitcoin, and trnsacted as Bitcoin.
But that means that every Lightning transaction is validated in the mempool of every Bitcoin node.
To conclude:
Every Lightning transaction is validated in the mempool of every Bitcoin node. That's how it works.