I dont think its anything to be worried about just because his reaction may have been a little cold.
Sometimes guys can appear to be emotionless to girls,
and girls can appear to be over emotional to guys.
And then there is the whole 'wanna look tough' thing where we hide our feelings if we do have them.
Maybe his mindset is "its a shame, but its not the end of the world, I can always see her next time and talk over the phone" or he is upset about it, but doesnt want to let it show (I think for alot of guys this is a situation they would want to hide how upset they are) or possibly he was just tired when he made the call.
Hope that helps, try to stay optamistic with things after all "It is better to be betrayed by a friend, than to suspect them"
