An unexpected booster failure mode would be well worth investigating.
Nothing I've seen or heard yet suggests that the test experience was outside expectations.
It raises the question if the explosion was trigged by the self-destruct sequence and not as mentioned on the livestream by disintegration due to free-fall and aerodynamic forces, did the explosion happen too close to the capsule so as it might have adverse effects on the capsule?
The explosion was not triggered by the self destruct system as has been pointed out to you repeatedly, and even if it were the system has been designed to work correctly in that scenario too (this is covered in the press conference).
The system is designed to be able to abort from a deflagrating rocket without warning (although that was not the design of today's test, obviously). Today, Dragon was already well clear when the stage disintegrated 11s after the abort. Just eyeballing the footage, it's probably a km away.
Thanks for pointing that, it's obvious now that you say it. The next question is why didn't they just explode booster using the self-destruct sequence while the capsule is still attached to test a more realistic scenario?