I think Buffy understood that which means she actually did the right thing. If your emotions are going to keep you from thinking, from acting on facts you taught her then how can she trust youI didn’t mean to appear as though that’s what I was saying, so I apologize for the confusion.
It’s more that at the time, Angel having a soul or not having a soul was irrelevant to Giles. Regardless of if Angel was ensouled or not, his face is still the same one that Giles saw while he was tortured for hours. It’s hard to forgive something like that, regardless of whatever outside factors there were.
Additionally, Angelus being Angel without a soul shows that every moment of every day, Angel is capable of that. That is within him and is his deepest darkest being. The thing that prevents it is his soul, but he is still capable of great evil. Especially when the switch is so tenuous (all he has to do is find true happiness or take some drugs like he does in Angel (lol)), it makes sense to me why it doesn’t matter. Angel could’ve come to Giles’s feet, apologizing and pleading and crying for forgiveness and it wouldn’t have mattered. At the end of the day, that being, whether Angel or Angelus, was still responsible for what happened and is still very capable of having it happen again.
The point I should’ve made more apparent is that, yes, Angel and Angelus are two different beings. But in that moment, it makes no difference to the wronged. Whether he was ensouled or not was irrelevant to Giles next to the trauma and sadness he has to now live with for the rest of his life.
I also don't buy the thing about Angel being capable of that, because the soul prevents him from being capable of that