Just so it's clear: There were two distinct dosing arms. No one from the 30mg arm was allowed to go higher. That would violate trial protocol.
What Missling was saying was that there were many in the 50mg arm who did not reach or couldn't sustain 50mg, so many in fact that the two arms were analyzed not only separately but also as one single cohort.
And since 50 is not much higher than 30 anyway (his assertion, which is a strange one, but typical Missling), he says he "pre-specified" a single cohort analysis.