Let me get this straight. You expect Plo Koon to leap out of his starfighter and attack his own clone troops? Right when that first shot was fire from the ARC-170's, Plo Koon was done. There was no way for him to get out. He was in an even worse position than Stass Allie.
Maybe Plo Koon just was not a great Pilot then ?
The attack on Obi-Wan failed miserably. If you watch ROTS again, you will see the laser blast from the AT-TE strike the cliffside, which knocked Obi-Wan off and into the pits. Yoda survived due to his masterful precognitive abilities and the fact that he could feel the simultaneous deaths of his fellow Jedi across the galaxy. The other survivors, I'm not too sure about. At any rate, Plo Koon was in a bad position in which he could not do anything.
Excuses , my point is not eveyr Jedi with Skills and Abilities measures up . Plo Koon comes from More PEACEFUL times , while Revan is battle Harded and is wise to know in his prime that betrayal can happen (Taught to him by his Best Friend Malek )!
Different times .