If that’s the best you can do.. lol.
Effectively they did have a predefined ECA. They used a third-party fully blind, above board, top set of experts who had absolutely no familiarity with the trial.
You prefer form over function. But the reality is the predefined notion is about avoiding bias, which they took pains to do, and which a regulator will indubitably take note of. It also happened before unblinding.
And as I recall, a number of other drugs, and I think even drugs in the Glioblastoma class that actually failed their trials but got approved anyway, did post hoc review which of course this was NOT.
So your arguments really do not carry the weight you claim.