Board Thread:Boruto Discussions/@comment-1018594-20161222205643/@comment-4912646-20161230000201

Madara's statement about Obito using Sage Mode once before is a mistranslation, despite being official. He actually says Obito had undergone "senninka", or sage transformation, once before (though it likely isn't meant to be related to Jūgo's ability). The databook went on to describe Madara's transformation as "rikudō senninka" a couple of times, so that may be what Madara was implying. The Crunchyroll subs were just directly mimicking Viz's manga translation of that scene. No idea why Viz decided to go with Sage Mode in that instance, but a weird mistake/change like that seems beneath the usual quality of their translations.