JSC: There was quite a discussion of the hut and safety during a lightning storm on the original Portal Store board, but Doug deleted it because he thought the questions were being asked for maybe a lawsuit. Fortunately most of the text was saved, and reposted in this thread:

Lightning: Thunderstorms on Whitney? Hut safe?

It is long, but a good read. What I pick from it is that if you were suddenly caught in a thunderstorm on the summit, the hut just might be the safest place to be. But of course, there are always exceptions to that. The best thing is to be off the mountain (at least off the summit and off the two-mile trail from Trail Crest) before the thunderstorms hit, which is usually after 2 PM.

Here is another short thread: 2005 Whitney lightning deaths