Okay Rabidcat, if I read this right, it seems like you had two separate problems: 1) Too slow response to a throttle chop in one auto; and 2) Allowing the RRPM to get too high during a 180 auto. Both events caused the examiner to take the controls and apply corrective action. With that in mind, he quite appropriately busted you. Face it, your RPM control is...well...weak.
You keep harping on the fact that you were "tired." Aww. Hate to repeat what you already know, but the helicopter doesn't care. And frankly, being tired is no excuse. (Someone should have mentioned to you that your checkride was not going to be a simple cakewalk in the park.)
A lot of people (not saying you, specifically) think that helicopter flying is just a lark - that it's just oodles of fun!...much more so than that boring ol' so-easy fixed-wing flying. Well guess what: Helicopter flying is fatiguing. It takes intense concentration, 100% of the time. If you perceive yourself to be tired, you step up your game and compensate for that. If you allow yourself to use "I was tired" as an excuse for poor performance either on a checkride or in your general, post-certification flying, you'll end up being a poor pilot.
We who do this for a living understand. We make sure we have enough stamina to do the kind of jobs guys like Gordy do. I've had plenty of 16 to 18-hour duty days (legal in the part-91 world) when my last landing was to our uncontrolled airport out in the middle of nowhere which has such pathetic lighting - and then I have to put the helicopter on the dolly on the dark ramp. And you know what? At the end of such days I'm tired too.
So. Get some more practice with your engine-out landings (sounds like you need it). Then go back and retake the checkride and kick some examiner a**. Show him what you can do! THEN come back here and proudly announce that you're one of us now. We eagerly await that post.