iPhone 5 Slide to Unlock then Homescreen Crash?

Hi all!

I'm a little bit worried with what I experienced with my iPhone 5 (iOS 6.0.2) awhile back.

Here's what happened:

1. Woke up the iPhone using the home button.

2. Lock screen pops up (still normal).

3. I do the usual slide to unlock.

4. Home screen pops up with the standard transition effect.

5. A split second later, the home screen goes black (backlight is still on).

6. A second later, the home screen appears but the backlight is heavily dimmed (my backlight is on manual/set control, however).

7. I lock the screen using the power button, wake it up again, slide to unlock, and the home screen appears normal again.

Is this just a bug in the software, or is this a hardware problem? It's the first time I've encountered this, and I've had the phone for almost a month.