This can be done two ways,
1) Using 1/4-round moldings that are cut and put in place after assembly. These doors would have been constructed using mortise/tenon on the frame then adding moldings to create the molded effect on the back and front.
2) Cut the cope and bead as the true shaker style, then assemble the panel, styles and rails. Next, add the 1/4 round to the front of the doors.
Either way is quite a bit harder to do. I can see where the contractor may have miss-understood your wishes by creating the door the more efficient way. Inexpensive way means not paying attention to the Sharpe finished corners.
Just showing him the door is not necessarily going make the problem his fault...You needed to highlight that the Sharpe edged moldings are an important feature. And you require this as a must have feature.
With that information he would then need to figure the best way to complete the doors with other techniques. I would assume he would have priced those doors quite a bit more. Just for argument sake how many doors are we talking about? And what materials are being used to make the doors?