Pilot decides. And unless there is formalized requirement, s/he will not check the outcome. De-icing crew is normally better trained and knowledgable than the pilot, who has only certain gudelines. So any inputs from ground are welcome and very valuable. I suppose the error management/risk assesment is less developed with ground crew, however the operation itself is very simple and so are the rules. No ice on wings, ever, at all.
FD (the un-real)