There has been a lot of reports lately, that blockchain.info has security issues. {Go check on reddit}
This is not problem of blockchain.info.
He sent his funds to
https://blockchain.info/address/1CAsRJ5Z9CXdhBwxrCVrf8kJNPBxYQJiH1The private key for this address is
5KRTiZDTBaEkVc********************AwbobA48yLFvTLS2CA lot of bots know this address and sweep funds from it.