I don't agree. Hermes has always cared as a really basic level about everyone, it's just generally not a priority to him over bureaucracy or his other passions. You have to remember, he was going to end up sending everyone into the Sun, not just Bender. It's pretty common for nearly all the characters to not care about eachother's lives, or at least feign that attitude. Hermes is no exception.
The fact that he acts with such contempt towards Bender throughout the series to me suggests moreso that this may have been a plan from very early on tbh. There was never any logical reason for it, as compared to say, everyone's dislike of Zoidberg. It's much easier to explain with this revelation though, there's no reason that him having saved Bender meant he had to be nice to him. It's all the more reason for him to act contemptuous to hide what he had done (it's not as clear that saving him was the right thing to do, even Bender was angry that he passed inspection, lol).
So, out of character? I don't think so. A contradiction to previous story elements? Probably. This show has very often been filled with contradictions though, I just don't think a consistent canon is nearly important to the writers as consistent character development, entertaining story premises, and above all, comedic value. I don't fault them for that in the least.