lighting - How can one light something in the foreground well while metering for lightning in the background?

A friend asked me how the lighting in this picture could possibly achieved: Source: http://www.theatlantic.com/infocus/2012/10/wildlife-photographer-of-the-year-2012/100392/

The description leads me to believe that there's no HDR or other technique that requires multiple exposures:

Hannes worked fast, framing the lion against the illuminated night sky at the moment a bolt of lightning flashed to the ground.

But it seems hard to believe that this could be done in a single shot with a flash.

How could one achieve a shot like this?