Well you said dragons could be relaxed by extreme stress situations right?.
In this case the dragon came out but he left a par of himself on his vessel.
Spines from his arms ened on his vessel arms, which made him furius, then the dragon saw his hands, they were human, and the ones from his vessel were draconic.
Insult added to injury he considered humans unworthy of life, having seen what it took his vessel to relaxe him he said this.
"I hate humans".
"I hate them for being killers of their own race".
"I hate you for being weak and make me suffer inside of you".
"I hate humans".
Thats all =]