I agree with bill and jim. 0.5 degrees off is not what is shown in the pictures - coping actually would not even have cared much at 0.5 degrees off. what is off is how the crown is sitting against the wall. you can see the coped piece is lower on the wall than the installed piece.
with the 2 small flats you have to play with it is difficult to get it right.
try this with a short piece. place the small flat against the wall about 2-3" below the ceiling, rock it back and forth to get the feel of the small flat on the wall. then slide it up the wall until it just touches - that is where it gets nailed. practice it a few times.
I do not nail the last 3' or so of the crown, until I get the next (adjacent) piece in. then, if I have to roll one of the pieces up or down to sit tight, you can do it.