...but Code Geass is Taniguchi's brainchild, and he (along with Okouchi) is credited with the Original Story. I can't disregard his creative contribution, and if he says that the manga's in the anime's timeline, I pay heed.

I mean, if you're gonna say that he wasn't the lead writer, neither was Tomino in Gundam's UC franchise. And despite 0079, Zeta, etc. all having different writers, they are definitely all considered within the UC canon due to the unity of setting, as well as having Tomino as the director.