One line examples rarely have enough context to infer. What about this sentence that needs an inferred subject?
田中さんは部屋に入ってきたかと思うと、いきなり窓を全部開けた。
"開ける" is transitive, so how would a proper translation deal with the lack of an explicit subject in the main clause?
- Just as Tanaka entered the room, Tanaka opened all the windows.
(given what ~ かと思うと... means this does not sound correct.) - Just as Tanaka entered the room, someone
(who we've already talked about)opened all the windows. - Just as Tanaka entered the room, all the windows opened. (
a paraphrase using "to open" intransitively)
For a translation, #2 makes sense to me but I don't like that empty inference of someone. For a paraphrase, #3 is better because then nothing is inferred; the missing subject is hidden. What do you think?