Transaction receipt is 0x1 but the execution failed. How is it possible

Question

https://etherscan.io/tx/0x20081e3012905d97961c2f1a18e1f3fe39f72a46b24e078df2fe446051366dca

As you can see from web3.eth.getTransactionReceipt

{ blockHash: '0xbd4c1f27df055d4aa7e1540808f1e63a6126e178ecb5324062d8df2525137ad7',
  blockNumber: 4891051,
  contractAddress: null,
  cumulativeGasUsed: 4035801,
  from: '0x2b5634c42055806a59e9107ed44d43c426e58258',
  gasUsed: 25236,
  logs: [],
  logsBloom: '0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
  status: '0x1',
  to: '0x1063ce524265d5a3a624f4914acd573dd89ce988',
  transactionHash: '0x20081e3012905d97961c2f1a18e1f3fe39f72a46b24e078df2fe446051366dca',
  transactionIndex: 151 }

the status is 0x1, meaning success. However, the gas limit was low(50k) for this transfer. So, what exactly happened there?

Answer 1

I think I figured it out:

aigangToken.methods.balanceOfAt('0x1f38ac62e62ecbc08e124297f84165b5f61cc96b', 4891051).call().then(console.log)

The sender didn't have any token balance.

So, Since the sender didnt have token balance, the tx simply executed this return: https://github.com/AigangNetwork/aigang-crowdsale-contracts/blob/master/contracts/MiniMeToken.sol#L220 Therefore, it was successful transaction