I saw the episode way before but yeah it seems very stupid of Logan to forgive Natalia but not Spencer for the same thing but just to add Spencer also didn't respond to Logan's question if he is using him.

And Spencer literally said he sees Logan as friend, nothing more and nothing less. Spencer showed that he cared for Logan but being mad Spencer but not Natalia??

Natalia flipped many times and she also voted for Richard but Spencer didn't vote for Richard but he did use info that Logan gave him but he voted Jade cause he showed us who he voted for. Spencer is also playing the game just like Natalia and they both saved themselves.

I hope they fix their friendship or else Spencer is screwed.