Lydia's very strange "death"

So Lydia and I finish up a quest in a cave, leave said cave and head for the great outdoors. As we're entering combat, but before any enemies are near, I hear Lydia give a pained moan, then I went into battle. Afterward, no Lydia, even after fast-travelling. So I go back to that cave, and there she was, dead. I loot her and move on.

Besides being very strange, which I know is a constant in Skyrim, I wonder if this will glitch things later on? I haven't tried to get another companion yet, and have read that others had issues recruiting new companions due to things like this.

Anyone else have this happen?

Lydia's very strange "death"