I honestly didn't expect this episode, though the climax of the last episode dictated it should be so. There's an awful lot still we need to figure out before we can truly understand everything Kiritsugu is compared to what his son, Shirou, will be. The Kiritsugu we saw in Fate / Stay NIght, albeit briefly, was not really someone who seemed completely consumed with his hatred of mages, though perhaps he was just hiding it really well. I am concerned about a timeline discrepancy, though, as Rin and Sakura are both already born, so Shirou should as well, but we haven't seen him yet, and he has lots of fond memories growing up of his dad, right up to the disaster that would consume him and the city which was supposed to be the climax of the last Grail War. I'm not saying we need to see Shirou, it's just interesting that, so far, Zero is only giving us one side of Kiritsugu (the business end), while not giving us the other side (the man who loves his kids, though we did get some shots of him and Illya earlier). Perhaps they wont, either, and just leave the moments between Shirou and Kiritsugu for Stay Night only. It would be an interesting way to do a "dual perspective", with, as Obi-Wan Kenobi put it, things told from a "certain point of view".
As for the episode, I also found Kiritsugu's turning on his father to be a bit premature, if the narratives we were given were all there was. IE, there's more to the relationship he has with his dad than we were told about. Something tells me this isn't the first time his dad has done something his son loathes, and while the first time can be explained away, being callous about the death of a young girl that Kiritsugu was quite obviously in love with would push anybody over the edge. Problem is, he makes the choice to kill his dad before he finds out about his dad's attitude. So, something wasn't being told to us.
Lastly, while I'm not a fan of Takeuchi's character designs, there is something incredibly attractive about how ufotable does the female figure. Doing a quick rundown of their anime works, aside from Manabi Straight which featured some intentionally unusual designs, I can't find a single one where I didn't like how they draw women. Don't know what it is.