FORESIGHT is quite correct, it is VERY easy to disconnect the autothrottles and move them manually. EVEN if you forgot the disconnect button (which is easier than picking your nose), you could simply overpower the clutch mechanism and move them just fine.
RAINBOE...if that lear couldn't stop its climb using manual throttles, the pilot should lose his license.
Some pilots just need a huge amount of training and the discipline to keep things working right.