Dispenser making "dispensing particles" when not dispensing anything

If you put a head in a dispenser and try to dispense it, it fails(as it's supposed to unless making golems), but it makes the particles for dispensing anyway.

What I expected to happen was: Nothing
What actually happened: It made particles.

Steps to reproduce
1. place a dispenser and put a head in it
2. activate the dispenser
3. look at the particles coming out of it.