No, I was talking about the decision to suicide, not the decision to become the Winter Knight. If Harry, in a normal frame of mind, would have thought killing himself was a good way to escape from Mab, then Mab should have read that in his mind. Also, if Harry would think about suicide in a normal frame of mind, then why did he NOT try to arrange his death (after he forgot about arranging it) again?
I think it is clear that a right-minded Harry would not contemplate suicide to escape Mab. Or if he were to do it, he would do it a lot smarter. Like tell Kincaid,
"Don't mention this to Murphy or Ivy (or me), but if sometime in the indefinite future, in the judgment of Murphy or Ivy, I have become irredeemably evil as the Winter Knight, then I want to call in the favor you owe me. If that happens, I want you to kill me. I am going to have the memory of this conversation erased, so I will not know it is coming."
Of course, if Harry later tried to call in the favor from Kincaid for something else, that would be a funny conversation.