[henrik_w]

Thanks for a good comment. Failing fast is great. In this case, since null was returned, the whole call failed gracefully (returning an error code to the calling party instead of simply throwing an exception).

The key point though: however the problem is detected, you need to have enough information to help you answer the question "Why did it fail?". You can add information in an exception, or in traces/logs, as long as you can tell why it happened, not just that it happened.