그렇게 당했으면 화날 법도 하지

The line, explained

At level three you can say 'it makes sense' in several ways, but -(으)ㄹ 법하다 has a colour none of the others quite match. It is the voice of someone weighing a situation and conceding, perhaps reluctantly, that a reaction is only natural. You hear it in narration, in news commentary and in the mouths of film characters who have seen a lot. Today's line comes from a detective looking at a victim turned avenger and thinking: of course they were furious.

그렇게 means 'like that, in that way', from 그렇다 plus the adverb ending -게. The ㅎ and ㄱ merge into a ㅋ sound, so it sounds like geu-reo-ke. 당했으면 is 당하다 in the past, plus -으면, 'if'. 당하다 is a useful verb with a passive flavour: to suffer something, to be on the receiving end, to get done over. 사기를 당하다 is to be scammed; 당했다! alone is 'I've been had!'. Here it means 'if you were treated like that'.

화날 is from 화나다, 'to get angry'. 화 is anger, 나다 is 'to arise', so anger literally rises up in you. The stem 화나- ends in a vowel, so it takes -ㄹ, giving 화날. Then comes 법, a word you may know as 'law'. In this pattern it means something closer to 'the natural way of things, what reason dictates'. 화날 법하다 is therefore 'it is in the natural order for one to be angry'.

Two small additions give the line its tone. 도, 'also, even', slides between 법 and 하다 to make 법도 하다, which adds 'I'll grant that, that's fair enough'. And the ending -지 turns it into a knowing remark, the kind you mutter while nodding: 'well, of course'. Compare the plainer -(으)ㄹ 만하다, which judges whether something is worth it or bearable. -ㄹ 법하다 instead judges whether something is reasonable, plausible or likely given everything you know.

Swap the reaction and the scene keeps its wisdom: 그렇게 당했으면 울 법도 하지 (no wonder they cried), 떠날 법도 하지 (no wonder they left), 지칠 법도 하지 (no wonder they're exhausted). As a modifier it describes believable things: 있을 법한 이야기 (a story that could really happen), 어디서 본 법한 얼굴 (a face you feel you've seen somewhere). It is a mature, measured pattern, perfect for when you want to sound like you understand more than you say.