Glowing balls definitely work like (t)arget function for the PC.
When they miss, they don't travel on but usually they hit the PC and then it boils down to resistance/immunity to fire.
I also don't think that death rays cast by monsters bounce but perhaps it's just something I never allowed to happen - I'd have to be cornered with the death ray caster pretty much next to me.
Most ADoM players know not to stand next to an emp lich if you value your attributes. Perhaps there simply wasn't any opportunity to test the "bouncability" of death rays cast by emp liches.
I'm curious though if perhaps the power of their death rays is insufficient to cast it very far.
I seem to get hit by death rays only within 3-4 tiles from the monster and bouncing action consumes more range so it could be that the power of death ray cast by monsters is not high enough to bounce and hit the PC on its way back.
"Hell is empty and all the devils are here."