The purpose of the perjury charges against Mrs. Zimmerman was to intimidate George into plea-bargaining on the main charges. It really serves no other purpose, and the state cannot afford the publicity that would attach to a real prosecution. Perjury requires intent to deceive, and it would be obvious to anyone reading the full exchange that there was no such intent on the part of Mrs. Zimmerman. She indicated that she didn't know how much money was raised, that the figure she offered was a guess, and that she would be more than happy to help the judge find out the correct figure. Perhaps the judge interpreted her statement as implying more certainty than it did, but if so the judge should have demanded clarification (e.g. "The exact amount doesn't matter if it's under $XX,XXX it, but I need to know if it's more than that. Is it possible it might be?") If the judge really wanted to know how much money was raised, he should have asked more specific questions and--if the answers couldn't be produced immediately--adjourned until they could be.
BTW, I wish the defense could have jurors informed of prosecutorial conduct during a case, and instructed that while it shouldn't necessarily expect prosecutors to always behave absolutely perfectly, they should acquit on all charges if the defendant is less of a criminal than the agents of the state involved in the prosecution. Seldom would defendants benefit from presenting such issues to a jury, but many innocent defendants would benefit if state agents had to avoid conduct which would alienate jurors.
I totally agree.