I've been there, quite recently in fact, but in a different way. A few weeks ago I was using a handheld "dotco" (airpowered 1-3" disc sander, 90psi shop air), mounting a maroon scotchbrite pad, trying to smooth out a shim for installation on an airplane at work, and the abrasive pad caught the material, and shunted the thing right into the finger holding the piece. I can't say I'd ever seen skin melt before, but it's finally almost healed, some 3.5 weeks later.
It hurts, but it's a good reminder to stop and think twice. COULD something go wrong? If yes, then err on the side of caution and turn it off =)
Glad to see you weren't hurt more seriously.
- Ryan