SpaceX hasn't yet released anything AFAIK. My wild speculation: not wanting to risk anything with both Trump and Musk being present at the launch site?!
But normally they do risk any other people? No, not at all. People are miles from where the robot could potentially go even after it is remotely aborted/blown up.
It's not just the area where the first stage might touch down, it's how far large pieces of debris might be thrown in a worst case RUD.
Plus, the Secret Service may be feeling far less tolerant of "eh, it's less than a 1 in BigNum chance of anyone getting hurt" odds than your average Tom, Dick, or Harry.
Trump, and Musk, and Cruz (US Senator), and Saltzman (USSF General), and a fair number of other VIP's.
Whatever was or wasn't going wrong in the booster during its landing approach, I'd for-sure bet that the "acceptable" parameters for a chopstick landing were tightened down quite a ways from the prior launch. (Or such a landing had simply been ruled out, by Security fiat.)
