He points out that a number of measures could have been implemented sooner had intelligence from the ground been clearer as to the severity of the situation, particularly in localised areas.
Mae'n amlwg o'r data bod anghysondebau o hyd ar gyfer rhai metrigau, sy'n debygol o gael eu hesbonio gan ddehongliadau o sut y dylid adrodd am ddata, ac arferion lleol.