I have not heard that although you may well be correct. Do you have a source so we can investigate that? Again I still say that at the very minimum he did it fast. A few minutes or even hours compared to almost two weeks is decidedly more merciful.
Oddly, I heard that on Boston radio not long ago. The commentators (Blute and Scotto on WRKO early morning),were talking, and it makes sense now I think of it, they were discussing Terri and what would happen. Scotto is the sarcastic one, and I think he's the one who brought up Kevorkian and said wasn't there that one woman who changed her mind, decided she didn't want to die, and Jack proceeded anyway. Scotto had a specific case in mind, but didn't name the woman. Perhaps there were just rumors that this had happened. I'm sure they're out there.