IMO (and aesthetics aside), the straight pipe through the dam is the most simple way to drain a pond. It is not the best way, but is certainly the most affordable and common, neglecting no pipe at all and just having a low spot in the dam.
But, I see your dilemma...if you remove the elbow from the design then it costs you money, if you don't remove the elbow from the design, it could leak again costing you a foot of water.
Ask your installer how they are going to eliminate the leak from happening again and post the plan here for some expert, and others, opinions. There has got to be a way to epoxy the joint and add a sleeve or collar of some sort that practically fuses the elbow to the underlying straight pipe. If they are just going to slap some silicone on it and walk away then don't waste your time on their "Fix" and negotiate a new plan.
Putting aesthetics back in play...the way you have it will look very nice compared to a corrugated pipe sticking out of the dam face. I would add a trash guard eventually, but it will still look better IMO.
