Well, you can call this an inside job if ever that has actually happened. But as what I mentioned above if you still care can you show us the BTC wallet address where do the funds stored since you said that you still have the access to your wallet. You can compare the "Total Received" of the wallet and the transaction made of the wallet if there is.
It wasn't inside job, it was a bug.
My wallet address is: 16io8zfbhStqe9WVdHN3JLzc29D73okaoy
You can see that most of the transactions there were made from blockchain.info IP address.
The thief address is: 1HKywxiL4JziqXrzLKhmB6a74ma6kxbSDj, and the transaction to it was not done from the same IP address (note that this is the same address as here:
https://www.coindesk.com/blockchain-info-issues-refunds-to-bitcoin-theft-victims/).
Checking on the link.If its totally a bug or you got victimized of that thief then you can complain on blockchain itself and as being stated their they would refund on those people or user who got victimized on such scenario.Just dont be scared as long you do have the strong proofs that you do own wallet then it should be fine.This is quiet new to me which blockchain do have some bugs and got compromised.