My driver's license is in your bank statement

The show: Family Guy
The episode: "Family Goy," first aired last Sunday on FOX.
What happened: Peter falls in love with a cardboard cutout of Kathy Ireland and neglects his wife. When he comes to his senses, he tries to have make-up sex with Lois but instead discovers a lump in her breast. Lois goes to the hospital, where Dr. Hartmann gives her a clean bill of health and announces that her mother is a Holocaust survivor. The doctor knows this because that's what the birth certificate in Lois' medical record says. Peter then becomes obsessed with Judaism, even converting. Peter drops Judaism as soon as the ghost of his deceased father Francis shows up to threaten him with eternal damnation if he doesn't return to the Catholic faith.
Why it makes no sense: Now it isn't enough to make absurd revelations about Peter's relatives, the way those revelations come about don't even have to make any sense. I still think that the idea that Peter is a Mexican immigrant (in "Padre de Familia") is pretty damn ridiculous, but at least the way Peter comes to that revelation was more organic than what happens in that episode. Since when is a mother's birth certificate kept in the medical record of one of her daughters? What's next? Will we learn that Chris is actually an ordained Anglican bishop when Peter goes get a lube change at Wal-Mart?
Also, I'm having a real tough time believing that a blueblood like Barbara Pewterschmidt could actually be Jewish, and a Holocaust survivor at that. The problem is not chronology, but characterization. I would think that a woman who's gone through something as horrific as the Holocaust would choose someone of more substance to marry than Carter Pewterschmidt.