For those who won't read the whole thing, here's the relevant part regarding sentences like "I was exhausted":

> The term ‘adjectival passive’ is often applied (perhaps not very felicitously) to active clauses with predicative adjective phrases in which the adjective derives from the past participle of a verb and has a passive-like meaning. There is frequently an ambiguity between be passives and adjectival ones. For example, The door was locked is ambiguous: as a be passive it says that at a particular time someone took the action of locking the door, and as an adjectival passive it says that during some past time period the door was in its locked state. Since the complement in this kind of clause is an adjective phrase, verbs other than be can be used (The door seemed locked, as far as I could tell), and so can adjectives derived with the negative prefix un- (The island was uninhabited by humans).

Thanks for the article, I'll give it a read later today.

I'll try to add some clarity to what I said (because passive voice isn't the only way to muddy the linguistic waters).

A passive voice doesn't make the sentence bad and often the passive voice does constitute perfectly fine English. When saying, "I was exhuasted" I may have no idea what drained me of my energy, in which case a passive is totally appropriate. However, it does lack clarity for the very reason you suggest "${SUBJECT} exhausted me" changes the meaning--"I was exhausted" doesn't specify who or what is responsible for the action of the verb. By not mentioning what exhausted you, the sentence looses a small amount of specificity.

"I am covered in green paint" is also passive because what covered you in paint? Something or someone is doing the paint covering, but by using the passive voice you can obscure the subject.

While we are recommending articles, Orwell has some enjoyable things to say about the use of the passive language in politics.

https://www.mtholyoke.edu/acad/intrel/orwell46.htm

Writing in such a way so that you can be understood isn't sufficient. You should always write in such a way so that you cannot be misunderstood, and using the active voice with its higher specificity goes along way towards that. However, exceptions will abound. As one of my professors used to say, "Language is the result habits--all of them bad".

Replacing 'done' with a different adjective in the second sentence makes it clear that that sentence is also not passive. E.g.

"Our work is difficult."