I've known birds come through the windscreen and hit the front seat occupants in the upper body/head, causing injuries. If a drone did so, and hard parts hit the pilot in the face, I doubt he would survive.
I've also known birds come through and hit the engine levers, shutting down the engines.
I've also had a sea eagle take great objection to the helicopter I was hovering in "his" territory (SAR training with a winchman out on the cable) and he circled us a few times before attempting to attack us and almost flew through the disc. Those birds are very big..... so we cleared off! It wouldn't have been so easy if it had been a real rescue.
Seagulls don't seem to see helicopters as a threat to themselves. They don't have airborne predators and if you watch a large flock of them they often bump into each other in flight. I've had a few fly lazily into the rotor disc over the years, they made no effort to avoid us.
During a rescue there is enough to concentrate on without having to worry about some idiot flying a drone in close proximity.