^ She lied to his face (more than once), and Castle's been consistently shown to be somewhat overprotective. And I think people are missing the fact the Castle was shown to be in the wrong for tracking her like that.
What? We're not saying the episode suggested he was in the right. Where did you get that idea? We're saying that by now, Castle should know better. Yes, he's been shown to be overprotective before, but that's exactly why
he should know better by now -- because in the past, his overprotectiveness has proven to be unwarranted and unfair to Alexis. My point is that instead of rehashing the same old story beat they've already done several times, they should've allowed Castle to learn from his past mistakes and not go so overboard with the protectiveness and suspicion this time around.