In most cases jeopardy attaches when a jury is empaneled, or evidence is presented to the Court.
English Common Law set the jeopardy point when a verdict was rendered. The Crist v. Bretz decision changed the federal rule to the point when the jury was sworn. The intent of the decision was to prevent the government from restarting the process ad infinitum until a guilty verdict was obtained while draining the limited resources of the defendant to endure the repeated attempts.
While it may represent "good lawyering", it is also a travesty of justice for Watada to escape prosecution.
This applies to prosecutorial actions, not judicial actions.
The entire jury trial can proceed up to the moment the verdict is to be read, and the judge can still declare a mistrial and the defendant can be put on trial again.
However, the prosecutor cannot drop the charges after the jury is empaneled or after presenting evidence in the hopes of refiling the charges again.
If this were not the case, then every time a prosecutor started to believe the case was going against him, he would drop the charges and refile when he found better evidence.