And as it turns out I was right; Nick saves himself as he's physically able, Pete dies if you don't. They were both in danger but Nick was quite capable of making his own way to safety (and does) thus I opted to help the one who needed it most. It's the same reason I saved Doug in Episode 1; Carley had one zombie on her ankle, Doug had several grabbing him, thus I assisted the person who needed it most. It's just too bad Carley didn't think to kick/stomp on it (incoming downvotes from "muh waifu" people).