Classical Conditioning on a College Roommate

This clip shows a college student conditioning his roommate to flinch at the sound of the phrase “that was easy.” Every time he presses a button that emits the phrase, he shoots his roommate with an airsoft gun.

Eventually, his roommate flinches just at the sound of the words that was easy.

This video has inspired many similar experiments that have been filmed and posted on YouTube, What ethical violations may have occurred during the making of this video?