[That makes quite a bit of sense, given all else she knows about Sougo. He wants to be important to people, and feels he's not. He wanted Lacus to be proud and pleased that he would try and protect her, and she interrupted and scolded him for doing it.]
Sougo, I'm sorry. I truly am grateful that you care enough about me to intervene. I wasn't happy about the fighting, but it was good that you arrived when you did.
If it's not too late, perhaps I can thank you properly now?