It sounds like you just had a sucky day. As much as my scientific mind tries to understand things, sometimes I'm convinced that all my insulin for the day gets stored in this hidden reservoir somewhere in my body (rather than being used), and then at the worst possible time, BLAM-O!, it dumps it out all at once causing a massive drop in BG.
As for wanting to sleep, I've tried setting my alarm for 2am to wake up and test, but that doesn't always work. Drinking a ton of water will help -- it may force you to wake up and get out of bed a few hours later to use the bathroom, at which point you can do another fingerstick.
As for your other question; if you can't figure out what went wrong, but it's an isolated incident, then just let it go. If it happens all the time, then it's time to figure out what's happening. Ask you doctor, CDE, or come here to ask us for help. No, you didn't make any obviously wrong decisions. (Well, when you were given T1 diabetes 13 years ago, maybe you should have politely declined...)