[binarybits]

Lightning's core innovation is the use of the Bitcoin blockchain as a cryptographic backstop for payment channels. If the other party in a payment channel stops cooperating, you can broadcast the current commitment transaction to the blockchain, which effectively refunds the current balance back to each party. There's a similar mechanism for enforcing the hashed time lock contracts that make Lightning payment chains possible. I don't know how you could do anything similar with conventional bank transfers.

[lambdadmitry]

Well, it can be solved the way current banks deal with fraud and chargebacks: rely on a very small number of parties misbehaving and set off a small percentage of money in the system to offset fraud. Another (complementary) way is a reputation system for "nodes" (as is the case in hawala). Both imply some sort of centralization, but so do Lightning incentives (see the discussion around "payment hubs"), so not much difference there.