This is not related to my other recently posted question about "working with a star developer".

In a similar vein, how do you work with someone who will only answer the specific question that you ask.

I worked with someone who, when you asked a question on a specific aspect of the system, would give you the answer just related to the specific bit you'd asked about. For example, when processing radar messages I'd ask about an aspect of message number RJ546 and he would answer just about that specific part of RJ546. He wouldn't mention anything about the other freaky parts of the message, or mention any related aspects of the other messages. Then you'd go off and work on the processing and all of a sudden all this other freakiness would pop up.

What's a good technique when working with this type of person?

BTW I later found out that the person who I'd come in to replace had quit because he got sick and tired of having these surprises pop up due to the lack of information provided by this person.

Edit: I forgot to add that the person was deliberately obstructionist and believed that job security came from hoarded knowledge not being disseminated.