Did Carmilla wrongfully lash out at Hector? Was Carmilla taking out all of her stress and anger wrongfully on Hector? I don’t understand the reasoning in her beating the shit out of him considering she needs his abilities and how crucial he is to her scheme. Why wouldn’t she just keep sweet talking him like she was before? 

I’m sure if she gave him a convincing reason, Hector would have complied. Instead she proceeds to completely destroy his trust in her. Why? Even Striga mentions beating the shit out of him was a huge mistake. How could the calculative and cunning Carmilla purposefully make such a mistake? It seems counterproductive, even if it was just a moment of indulgence.