Well now that I'm home, have eaten, and had a glass of wine, I'm finally calmed down. I'm mad at one of the students (a bit), and very much angry at myself.
It the past, I thought I was always pretty good at spotting forged notes, etc... If a kid brought me a note that claimed to be signed by a parent, I could usually tell and followed up with the parent. Similarly, I had parents sign doctor's names to med orders and the like and I can usually spot those (especially for the popular pediatricians in the area) and call on those.
One got by me yesterday. A student had his mother's name forged on a consent form and I didn't catch it. I found out today when I talked to his mother that she hadn't been the one to sign it (and hadn't known about it). Fortunately, after her initial anger she seems to have directed all the blame at her son, so hopefully, I'm not getting in trouble over this. But I was shaking for minutes after I hung up with her.