It is always important for the manager to build good working relationships with colleagues. They must not be thought of as subordinates but valuable resources.
Half the issues in mananement is understanding the staff that work in the team, what is happeneing in their job, personal life – (if appropriate)and by doing this realising how they will respond to requests.
I believe that I would have made the point that he was a valuable memebr of the team and explained the importance of the task allocated to him. I would have diffused the situation by still asking him to do the task and having a follow up meeting with him to take agree a way forward, with expectaions that he would either accept my task or come up with a better solution
Regards
Ace Hussain