I'd be quite surprised if Amazon didn't have a similar team, even if just a dozen or two staff, if they are experienced, that's all that's usually required. The savings lost to poor public relations, and improved customer relations, easily make up for the cost of the team.
Obviously, if it's legitimate, you would have the ability to fix the issue right away. However, what if there were enough red flags that it didn't seem entirely right?
Not saying that this is the case either way, but I'm curious what the standard procedure is in that case.
For this case, my team would have resolved it within 24-48 hours, based on the information that he's posted. It doesn't seem overly complex, assuming no fraud (or his account was mangled in a data transfer or deleted in someway and he hasn't mentioned that), and the resolution takes a few hours of someone making the new account and searching for titles to add to the account.
As a longer answer...
We didn't deal directly with public relations or issue press releases concerning significant public domain complaints, as to the best of my recollection, we didn't have a large PR nightmare to deal with while I was with the team. So that aspect I can not comment on.
If it was an issue of fraud, and we had several instances of fraudulent claims, we would clearly state that was our conclusion to the customer (or claimed customer). Our company did not actively pursue legal action against fraud cases, including a significant internal fraud case that was discovered, because of the possible negative publicity and loss of public reputation/brand quality.
Though through escalation, if I could not personally (as head of the team) find a solution to the issue and we felt it was fraud, we would offer to arrange an in-person meeting with the customer and ask that they bring their (or a) lawyer as the department VP, along with our legal team, would like to discuss the issue in detail. I don't remember more than one client coming in for a meeting in a two year period and we had security officers in the next room (with blinds down and listening in) in case there was a problem.
I can easily imagine several scenarios; the one I'm having trouble imagining is one where they can't tell him why he's locked out.
Honestly, the only thing that is even remotely reasonable is an investigation by a three-letter agenchy.
Initial guess, from some experiences with chargeback happy customers, is that the guy started initiating chargebacks before giving amazon a chance to resolve his problems, and amazon is refusing to help him until he cancels the chargeback process.
That said, regardless of their size, they should expedite this type of check, specially for accounts that are not new!
By the tone of your comment, I'm assuming the "part of the story we're not hearing" involves the customer doing something wrong, rather than Amazon? If that's the case, I can't really think of what that thing might be that would give Amazon the right to lock this guy out? Also, why would he bring this issue to light and risk exposure if he really had done something so wrong?
I find it much easier to believe that a large corporation allowed an individual customer to fall through the cracks than some fraudster launching an elaborate plan to scam Amazon out of $1000 in e-books.