Not only did this user not merge their account (because that doesn't happen, as many people here have noted), deleting your account is a pain and a decent amount of work that is difficult to do accidentally (see this walkthrough[1] about how explicit the process is: you have to click a checkbox for each product you currently use), and there is an account restore procedure after deletion[2].
Now, it is possible this user was confused and did all these things, then waited too long to try to restore their account, but there's not much else you can do for a person like this. You don't want a deleted account to be restorable for too long. They ask about Drive documents, but a mainstream and obvious backup for that does exist (not sure what it does if your account is deleted, though). Maybe make multiple sign-in disabled by default so that people won't accidentally do it? That's just going to annoy a different class of users...
Regardless, if people are going to reflexively vote up every bad user story in the google product forums (and why stop there? there are help forums all over the internet!), the front page is going to be...not very interesting.
[1] http://howto.cnet.com/8301-11310_39-57388685-285/how-to-back...
[2] https://support.google.com/accounts/answer/1212172?hl=en&...