I don't disagree with you factually. I just felt that he didn't deserve the beating.
But his wording was very careful and implying that the might be wrong and that it was the worst case: "If it’s taking this long to get the 1st patient injected, it may take much longer to get the trial fully enrolled. If so, we may not get interim results until early 2020."
In any case, we will know that results are very positive if they apply for breakthrough designation after the 5 first patients got treated. But if a higher dosis is needed to achieve a significant reduction, it will take a while due to the dose escalation design. The more I think about it, the less unreasonable his estimate seems to be.