From the linked article:

"In ordering a new trial, the three-member appeals court cited false testimony by the state’s expert psychiatric witness, who said Yates had patterned her actions after a Law & Order television episode in which a woman drowned her children and was found innocent by reason of insanity. It turned out there was no such episode, and the appellate court said the trial judge erred in not granting a mistrial once it was learned Dr. Park Dietz's testimony was untrue."

Park Dietz is a highly accomplished guy. (link: http://www.jhu.edu/~jhumag/1194web/dietz.html) What was he thinking? Sounds like the appeals court did the right thing. What a mess.