Im sorry to hear that. So many things went wrong here. This is the way i see it.
Basically what you did was introduce a friend of yours to your colleagues with good impressions on just about everything. This is like introducing a friend to me and telling me his a great person even though you know deep down inside you know your friend doesnt have the best personality in the world. What you could have done was be sincere and told your colleagues that D is a great person overall but he does have his drawbacks. That way they know what to expect and are ready and prepared to handle D. Along with that you could have inspired them on a different point of view. You guys are working with JavaScript :/. Doing something with D would have been an extraordinary achievement. Thats like accomplishing a task with a common method. But sometimes you have to take a leap of faith and accomplish that task in a new way. This would have given you and your team unique in a way and probably have given you a good image.
