Yes, and since I looked it up, if the ball won't stay there when placed, and rolls down the hill, you attempt one more time to place it, and if it moves again, then "it must be placed at the nearest spot where it can be placed at rest that is not nearer the hole and not in a hazard" (rule 20-3(d)(i)).
So placing might be the better option, a little more certain than dropping. Unless there's an area behind where dropping will give you flatter ground that will make the shot easier. But it sounds to me like the flatter ground here was in rough. And even if the nearest spot it will rest is down the hill in the rough, I'd rather place it there than drop it (might get a better lie).
i guess the chip was the wrong choice even though if i had it again I would have played the same shot that I played. The ball was lying against a thinner part of the branch with the top half of the ball visible. The ball was on such a severe slope that I would not want to place it after it dropped and rolled down twice. i guess the better option was to go as far back as I wanted which would have been the flat area.