made a salad.

Although the hypothetical simple past ("would upset") is fine, your example sentence mimics this structure. Sometimes people speak or write without carefully thinking through the grammar.  
That being said: 

If he had known it had upset you ...

represents a different situation.  In the first case, "would have upset you" suggests that he was immediately aware that you were upset, but "had upset you" instead suggests that he was not immediately aware that you were upset.  To diagram it:

"it would have upset you" 

He did something.
You became upset, and he noticed.
He felt bad about it.

"it had upset you"

He did something
You became upset
He later found out you became upset (by what he had done), and felt bad about it.

Unreal conditionals and perfect tenses each aresuch, often RJ-11 and RJ-45 modular jacks are located side by side on the rear of a piece of electronic equipment or in another limited access area. Both aesthetics and system architecture dictate placement of modular jacks and, therefore, selection of their location is a limited option.
Since access to the modular jacks on a piece of electronic equipment is often restricted, insertion of a modular plug into a modular jack is frequently performed without visual verification. Thus, it is possible that during blind installation of a modular plug into a modular jack, an equipment operator may incorrectly align an RJ-45 plug with an RJ-11 jack or an RJ-11 plug with an RJ-45 jack. Misaligning an RJ-45 plug with an RJ-11 jack is of little concern because an operator