The aim is terrible
The fireball always passes your and explodes 3-5 blocks behind you
Also sometimes you heat the ghast fire a projectile but the thing doesn't come untill the ghast sees you
I will try to upload a video but it's kind of hard to reproduce
The sandstone in the middle is normal block
In the right and left those blocks are made out of putting 2 slabs together
You can see the difference in the color
I managed to find a video of this bug being shown i re-uploaded it
The exact thing happenes to me all the time