Person 1 「ところでなつみとさやこは？」
Person 2 「あ、やりすぎた二人なら向こうで正座させてます」
Person 1 「そ、そうか。大変だな。」
In context: Person 1 had been knocked unconscious by なつみ, さやこ, and some others (as a reaction to him unknowingly stepping into the room they were all changing in). When he came to they were apologizing to him and he said that he was to blame and that they shouldn't be apologizing to him, when he noticed that two of them were missing the last few lines of the scene as seen above were said.
Now when I look at this I could see it being interpreted in two ways.
The 大変 is talking about Person 2 (He is expressing sympathy with her due to his actions leading to her having to punish the other two)
He is expressing sympathy with なつみ and さやこ due to them having to be punished even though he believes that all of the fault lies with himself.
My problem is understanding which understanding is correct(and if neither of the above, which is it).
It's clear that there are two possible groups that it could refer to as Person 2 is having the other two 正座. If he was just being told that they were being punished (by some other person and not the person who was punishing them) then I would naturally default to it being (1), but in this case I am unsure. How do other people look at this? Would the sentence be worded differently depending on whether it is case (1) or case (2) ?