So if anyone cheated it was Obama...

And he really didn't cheat either but he did have a one question advantage. From Byron York;

A few points. First of all, it appears that some commentators believe
there was an actual "Get Smart"-style "cone of silence" at Saddleback.
There wasn't. Pastor Rick Warren was making a little joke when he used
that phrase. But he was assuring the crowd that McCain was not hearing
any of the questioning of Barack Obama.

Next, McCain, like
Obama, knew the first two questions that would be asked of him — the
"three wisest people" question and the "greatest moral failure"
questions. Both men knew exactly what was coming at the start of the
appearance. This morning I talked to A. Larry Ross, who is the media
representative for the Saddleback Church, and he told me that Warren
"gave both candidates the first two questions because he didn't want
them to be nervous…so they would be at ease." Ross says that in
separate phone calls with the McCain and Obama, Warren also went
through the four general categories of questions and said things like,
"I'll probably ask you a question on this, or on that," but gave no
specific wording.

In addition, according to Ross, Obama knew a
third specific question that Warren would ask — the one about a
"president's emergency plan for adoption." "[Warren] felt that since
that was basically asking for a commitment, he felt that it was fair to
tell them in advance that he was going to ask them that," Ross told
me. So Warren told Obama, and planned to tell McCain when McCain
arrived at Saddleback, but wasn't able to because of other
distractions. So according to what Ross told me, Obama actually knew
one more question in advance than did McCain.