I feel like a lot of people don’t quite get what a butler is. The role tends to get rounded off to ‘male servant’ pretty regularly in some media, whereas actually butlers are typically not just servants but chief servants. The butler was generally in charge of either all male servants or just all servants, period, in the household of an aristocrat or other very wealthy person. This meant that butlers have often been fairly powerful and influential people, and sometimes even had a manservant or two of their own.
(Also, fun fact: Mary Roberts Rinehart, the early 20th century mystery writer who is widely credited with popularizing the whole ‘the butler did it’ trope was nearly murdered by one of her own servants, a chef whom she had passed over for promotion to butler. He came at her with a pistol, but it jammed, allowing her chauffeur time to wrestle it away and restrain him.)
You didn’t answer the key question things brings up: did she popularize the trope before or after the would-be butler tried to kill her?
according to wikipedia, before
There’s something glorious about the fact that the author who popularised “the butler did it” had a servant who a) failed to become the butler and then b) failed to do it.
If he’d been butler material, he’d have finished the job.