I have had it on two separate occasions with no reaction. The first time, I just took the bartender at her word. then I ready the controversy, but since I hadn't reacted the first time, I bought a six from my local liquor store. Drank 3 of them with no problem. So take it for the anectdotal single data point that it is, but I liked it a lot.
It sounds to me like hypnogogic or hypnopompic hallucinations (as was mentioned up-thread). I've had them for years. I see animials, insects, or people when I wake up. Since I've had some practice I usually can control my reaction enough to avoid screaming. Although both my wife and my younger borther (from my childhood days of sharing a room) could tell...