No they fell into that. Heck the woman started to say, “We are suppose to be non-partisan” and then O’Keefe cuts her off. He blew a chance to get on tape an Acornidiot admitting their partisan bias. But I suspect under cover filming like that is very high pressure and they have done a great job. I am just sorry he let this one little opportunity slip by.
If she has been tried and acquitted it is over. She is not guilty as a matter of law. She can write a “How I Did It and How You Can Too” book with impunity. Jeopardy attaches in a jury trial when the jury and alternates are selected and sworn. In a judge trial jeopardy attaches when the first witness is called and testifies. If the first trial resulted in a mistrial there might still be a case.
Believe it or not, a confession by itself is not likely to result in a conviction in any case. Many criminals or wannabe criminals like to boast or inflate their deeds, and there are a lot of kooks who dramatize their sad lives with claims to murders or other lurid events which are completely false.