If amazon.com is down (as it is right now), searching for books in the careers returns no results and reports no error. It would be better to show an error message to let the user know what went wrong.
In my testing I was unable to repro this. Currently we do show an error message if we can't query Amazon's API for whatever reason (which I was able to repro), but it can be a bit hard to spot as the error text is plain black at the moment. We'll go ahead and make that error message stand out a bit more.