It puzzles me that there does not seem to be a proper derivation and discussion of the error term in the paper. It's all treated indirectly way inference results.
The paper has an odd feel about it to me too. Doing a gate estimation as a text explanation without a diagram makes it too easy to miss some required part. It wouldn't need to be a full gate level explanation but blocks labeled 'adder'.
Seeing the name de Vries in the first paragraph didn't help my sense of confidence either.
