Ok for anyone who doesn't know the idea behind this. the basic thing is to observe certain events or objects you have to interact with what you want to observe. and by interacting with the object you can change its original intention.
for example to observe an electron you have to interact it with a photon. by this interaction you change the momentum of the electron etc.
so in real life where it is known as the hawthorne effect. imagine the scenario. a guy is in a relationship. he goes to town with another girl for an unknown reason. someone spots him in town with this girl and tells the guys partner, this leads to a string of horrible consequences.
if the guy hadnt been observed nothing would of happened. surely the observer is at fault here