Q:

Wondering whether my perception is correct on this short text

"We are working in a very big ocean and within a very large search area, and so far since the aircraft went missing we have had very few leads which allow us to narrow the search area," he said.
http://www.bbc.com/news/world-asia-26908884
Which of the following perception of mine is correct?

We have had very few leads so far and therefore it is difficult for us to narrow the search area. 
We have had very few leads so far and that has allowed us to narrow the search area.

A:

As is signalled by the absence of a comma, the relative clause which allow us to narrow the search area is a restrictive clause modifying the NP very few leads. The speaker is only talking about leads of the sort which allow us to narrow the search area, not about other leads.
Presumably, however, each of these leads only allowed us to narrow the search area by a small amount. Since there are only a few of them, we have only been able to narrow the search area a little bit, so it is still very large—216,000 km2. That’s a circle with a radius of more than 250 km.

