Sadly, I do not know what is wrong neither… ! 
You didn’t mentioned in your issue description, which browser do you use for your MetaMask wallet? (Chrome, Edge… ?)
Another question, the device you analysed with Recuva is the same device you used to create your MetaMask wallet?
Have you ever been using this wallet on another device? (Phone, another desktop/laptop, tablet…)
And also, did you ever created any other MetaMask wallet (with different seed phrase)?
Just to shear what I understood about the issue, there is a possibility while using multiple MetaMask wallets on the same device (or even different devices but with synchronised browser extension across the devices) that an Account from one seed phrase might be imported to another seed phrase with no mention it was an imported one.
In my case it was a seed phrase I created while I was even not sure I would use any crypto. I just followed a YouTube explanation to see if it was difficult to create/use MetaMask just for fun. Of cause I never noted/saved this seed phrase (it was on Edge browser synchronised with Chrome account via an e-mail, and for some reason, probably synchronisation option, MetaMask created a nkbi… folder instead of normal folder using with Edge that folder is called ejbal….) Then, later, when I took the decision about the crypto, I used Chrome browser to create a real MetaMask wallet, and printed out the seed phrase right away. What was strange, the seed phrase was showed twice, the second time on the « black output » like this
Do not worry, it’s an empty wallet 
There where the all problems started for me. Actually, the Account 1 that was displayed on MM never was one from that seed phrase, but from the my test wallet! I learned it much more later… it is not mentioned on GitHub and I had no time to update it there.But it’s not all. I created an another MM wallet later, on different Chrome profile. Account 1 was right. No black screen neither. But later, the MM extension didn’t accepted the password, so I had no choice but to import the seed phrase. And here - an Account 1 from my test wallet was shown as native one for this new seed phrase.
Do you recall if you had some similar experiences while creating your wallet (black screen or seed phrase displayed multiple times) ?
The experience of another user seems to be similar. Multiple wallets and the « jumping Account 1 » from one seed to another: http://github.com/MetaMask/metamask-extension/issues/3127#issuecomment-370819730
Also, some other experiences, like
seems to match the same scenario.