Book Review: Prior Bad Acts

I'm reading Prior Bad Acts by Tami Hoag right now. Generally she's an author I enjoy, even though she's a little dark so I have to take her in small does. The plot of this book is best summarized as this: a mother and two children are killed in a really horrifying, disturbing (so disturbing I wonder about Hoag's imagination) manner; the police arrest a suspect; suspect is charged with murder; the prosecution tries to enter into evidence the suspects "prior bad acts" such a larcency, indescent exposure, being a Peeping Tom, etc; the judge refuses to admit the evidence; the police and the community go apeshit over the judge's ruling; the judge gets beaten up in the parking garage on the way to her car.

Okay, so maybe this would seem like a thrilling and exciting read to you, but I'm taking Evidence right now, so it's causing me some problems. The first problem I have with the plot of the book revolves around Federal Rule of Evidence 404(b), in which character evidence, as a general rule, is excluded. And "prior bad acts" is character evidence.
Evidence of other crimes, wrongs, or acts is not admissible to prove the character of a person in order to show action in conformity therewith.
So I'm kind of wondering how Hoag really expects us to believe that this judge's ruling would be SO controversial that it would cause prosecutors and seasoned cops to lose their minds. THE RULES OF EVIDENCE PRETTY MUCH DEMAND THAT SHE EXCLUDE THE EVIDENCE. It's just beyond my imagination that a prosecutor is that upset over the ruling when it was his job to argue that it should fall under an exception to the general rule.

This is really bothering me. In case you can't tell.