Okay, some more info between talking to him and questions raised by my office mates and y'all.
He has had episodes of hypoglycemia before. Several years ago, he had this happen to him. At that time, he was only put on short-term medicine, and we borrowed a glycometer (sp?) from his parents. We should have kept it.

That was all they found for him was to regulate diet for a short period (Don't shoot me, I'm just the messenger. LOL!) and the symptoms went away. This has been the first time (the episode 2 weeks ago, that is) that he's gotten that bad again. He *does* have a history of this type of episode, just not normally this bad other than the time it hit years ago.
What might he be hiding from me? I think it's more of a white-coat fear (which he does have), squeemishness (he is *very* uncomfortable in dr's offices and has a hard time even watching the kittens get their shots. Blood makes him very light-headed), and denial. Last time he blacked out mentally, he ended up out sick for a month to get things back in order. He's afraid of it happening again.
I didn't go with him to the drs offices in the past. In theory he's *supposedly* been having his dr checking his bloodwork and sugars and stuff. Now, I'm pretty sure he hasn't been. He *has* been going to the dr regularly because of some medication he's on that requires a checkup every few months, but I don't think bloodwork is required in that.
He is not going to bury his head in the sand on this one. Not anymore. Last night and today made it totally clear just how much he's denying this and trying to hide from what's happening.
BTW, he's working from home today, his boss knows what's going on (I emailed him as he and his wife are friends of ours), and I'll be calling to check on him every hour or so. My manager knows what's going on and is concerned about him as well. Slightest hint of slurring speech, and I'm getting home with him. He starts dropping again, and he's going to the hospital.
Another piece of info is that apparently all he had for dinner last night was some cupcakes. He claimed to have eaten something else, but I'm willing to bet that he didn't and he lied to me about eating. So when he was hyper last night before the movie, that was the sugar high. When he started going down again, that was the low.