Bears might not be able to speak, but they can still communicate through body language. It was clear that even though they were out of the water, the bears were uncomfortable. They were shivering and trembling.
Part of that was because of the cold, but it was also easy to tell that they've never met humans before. The humans may have rescued them, but the cubs had no way of knowing what would happen to them next. They were so nervous they couldn't even look at their saviors.