The Bar Tab: Payment Channels

What actually stops a channel partner from broadcasting an old state where they had more?

• The 2-of-2 multisig, which needs both signatures to close
• Revocation: the other side holds the secret to take everything if an old state appears
• Miners, who check which state is the newest

You force close your channel because your partner has vanished. Why do your own coins not arrive straight away?

• The network charges a waiting fee
• Your own output is delayed so your partner would have time to punish you if this were an old state
• Force closes always need a second signature from a miner