And they would have probably needed a zero-zero ejection seat (can eject safely at zero altitude and zero groundspeed). And they would've had to eject before the fuselage rolled over and pointed toward the ground, otherwise they would've been ejected toward it (about 3-4 seconds). And they would've had to have been prepared for, and expecting, the possibility of ejection; I don't know if anyone has ever ejected from a fire bomber.

Finally, even if they managed to eject, they would be parachuting into a forest fire.