I understand that after a channel is created, A and B need to agree and sign to create a new transaction. The new transaction overrides the previous transaction. A or B could quit the channel by broadcasting the transaction onto Bitcoin network so that the transaction is final:
txn 0: A:0.5, B:0.5 txn 1: A:0.3, B:0.7 txn 2: A:0.9, B:0.1
A or B quit channel, broadcast
txn 2, so A will have 0.9 and B will have 0.1
But what if B quit the channel, broadcasting
txn 1 rather than
txn 2 on to the Bitcoin network? Wouldn't the
txn 1 becomes final and B could walk away with 0.7?