Raw data for the transaction you posted is:
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
With input signatures stripped and hashType added:
01000000010a76e7737d25ebab31a954919f9126940ffbe136a9523d9c3940e8af912ccace0100000000ffffffff0210270000000000001976a914c36291d28c66530f3e79c89aa34b763e20e574dc88ac23ed9200000000001976a914a341c6fd7f94118af99a6cfeaffcebcc8714817888ac0000000001000000
I tried to hash these in various ways, but nothing returned the hash that they are returning in the tx_hash parameter.
It really seems that it's an issue on Blockchain.info's side:
https://github.com/blockchain/My-Wallet/issues/72http://bitcoinewz.com/news/blockchain-info-api-payment-txhashOR the hash is just something they use internally, but it's unlikely, because I couldn't find any documentation about it, and everything that I did found suggested that tx_hash should represent TXID of the transaction.