Anything involving fuel is dangerous. Demo-2 is first time that humans are on the rocket while its being fueled. The escape system is on while fueling and defueling since those are high risk times for the rocket.
Even when boarding commercial flights, crew tells you not to fasten seat belts if they’re still refueling. Just in case you need to evacuate (of course it’s just a token concern, I would t expect to survive an airplane bursting in flames even if still docked.)
people have survived even crazier situations, like an airplane cartwheeling down a runway AND THEN bursting into flames. (100+ survivors, out of ~300 IIRC)
