スネイプがそれを盗んだところで、それがどうしたというんだ。 (Japanese TL)
What did it matter if Snape stole it, really? (Original English)
I'm struggling to understand それがどうしたというんだ. What does it actually mean, and is there are way to break it down logically? Should I just learn it as a set phrase?
I started thinking about どうしたの which means "What's the matter?" or "what happened?". I've never been able to make sense of those translations and just learnt it as a set phrase. I can't fit either translation into the sentence above and get any sense out of it either.
Are there any other phrases involving どうした that would shed light on things. Any general pattern?