That lots of debris was flying around isn’t just speculation ...
The speculation regarding engine damage makes a lot of sense. It would explain liftoff with three engines out, and the gradual loss of three or four more.
They desperately need to fix the debris issue. Detonating the rocket at 10 miles altitude probably means they can’t examine the engines for debris damage.
I’m kinda coming to the conclusion that the biggest hole and biggest problem in this project is the launchpad.
Right. I saw some of it as soon as I watched the launch the 2nd time. (I was actually more wondering about the extremely slow liftoff.) The quite possible engine(s) damage then started getting mentioned by more knowledgeable observers (than I).
Recovered rocket debris, if some can be recovered, might still lend clues. Or perhaps some of the telemetry will contain a few clues. SpaceX should know what they are looking for.
OTOH, I wonder why the issue did not present itself at the static test firing?