Establishing a link between malpractice and harm is

proximate causation

Explanation: If you drive on the highway, for example, you have a duty to keep a proper lookout. If you fail to notice a vehicle stopped in front of you, you’ve breached that duty. If you crash into the vehicle, the damages were proximately caused by your breach of duty. You would be liable for damages caused by your negligence.

nope, but i have cleaned my brush in my cup of not as potentially harmful but nevertheless, very upsetting for scottish/british folks. especially if you've used the last teabag for it

explanation:

there could be something in that . . i am indeed an old scottish man!

there's a bit of bolshie-ness with it too though. i won't let go of the old ways . . tea and whisky . . whether the young whippersnappers like it or not!