This is how I know you're lying.
I know for a FACT who the doctor is.
I don't care who you think the doctor is, or who you suspect it is.
I know you're not the doctor
I know I'm not an FG
and I know who the doctor is.
I hold all the cards, you hold none.
As for change of reasons:
I voted for you at first because I know it doesn't make a matter in the overall game
I'm voting for you now, because there's no reason to suspect me, and plenty of reason to suspect you, and yet you're trying very hard to make yourself seem innocent.
If you're just an innocent, stop trying so hard. It won't make a real difference
If you're an FG, you'll keep up with this stupid attempt at saving your life, because you might 'think' you know who the doctor is, but I DO know who it is.