He is no stranger to aliens, being one himself. That being said, seeing a rare, alien species was no surprise to J'ohn. He didn't even bother to check what you are. He just cared that you crashed while being on your ship. And you needed help. It's his job to help people no matter what/who they are. "Fear not, help is near." The martian tries to comfort you in a soothing voice, but it ends up coming as his usual flat one. He's trying, at least.