When in doubt, blame the chick with the facial markings.
The final few episodes of the Star Wars: The Clone Wars series concerned the framing of Ashoka Tano in the bombing of the Jedi temple, and subsequent related crimes. It was one of the better story arcs of the series but the writers left didn’t include a crucial piece of logic that would make the .
During Ahsoka’s trial and everything else leading up to it, it was never established what Ahsoka’s motive was for the bombing. Most of the evidence considered was circumstantial and Ahsoka’s motive would be an important piece of information in any trial, given that it was completely out of her known character, and given Ahsoka’s past dedication to the Jedi order.
Strategic bombings aren’t meant for killing as much as it is to send a message. If Ahsoka was behind the bombings she wouldn’t deny it at the trial. She would claim responsibility for it and protest whatever ideological reasons she had for doing it—just as Barriss Offee did so when she was captured and brought into the courtroom to testify as the real perpetrator.
The writers should have had the investigating Jedi look for what possible temple insider—Jedi, Senator, or otherwise—would have known to be at least semi-rogue to what the Jedi were doing (there are plenty of Jedi and politicians that come to mind immediately). Thankfully this huge oversight didn’t take too much away from the decision Ahsoka made after she was ultimately acquitted.