Ridiculous, it’s on the headset operators to keep the devices at safe levels. That’s like me sending you a fax and you suing me for a papercut you gave yourself with it.
The major difference is whether it was done with malicious intent, which is a factor in legal culpability.
It's not even close to your suggestion. A papercut would be a potential injury in normal use of a fax machine, from wanted or unwanted faxes. That would be like someone hurting their wrist when holding the phone up to their head.