You can’t assume you can trigger a system after it has undergone extreme structural loads or failure. So waiting until that happens while rocket is, charitably, careening does not ensure staying in any box.
I doubt they had any uplink or downlink during that mode so there’s no data to be had.
So if you "can't assume you can trigger a system" in this situation, you rely upon an automatic system, not a RSO. Which is exactly what SpaceX did. I'm sure this was fully documented in the approval process.
SpaceX acquired a huge amount of data that would have otherwise been lost if the RSO was "quick on the trigger."
Example of a different rocket failure where the range safety officer let the rocket survive until it exceeded the safe trajectory box:
"Astra Rocket 3 LV0006 drifting launch & failure (NASASpaceFlight footage)" https://www.youtube.com/watch?v=HxVoBlgzZlQ