Other mistake: When Devito sends Arnold into the house to get his stuff and go with him to New Mexico and Houston, Devito quickly jumps into the car to drive off. (You can see on the long street behind him that there are no cars coming). Yet, not one second has gone by and you are looking at him from the front of the car and Linda and her sister pull up behind him blocking him in the driveway. They turned in from the left which was the same stretch of street you were looking at with no cars on it just one moment earlier. (00:48:40)
Other mistake: When Julius visits the orphanage where Vincent grew up, he begins to talk to the nun about the bed where Vincent slept and how it was near the fire extinguisher and alarm. While talking about it, he makes a motion as though he is pulling the fire alarm, but doesn't actually do so. As Julius and the nun are exiting the room, the alarm pull handle falls down on its own (no alarm goes off).
Chosen answer: Although I wouldn't call one a bad guy, Professor Werner is the the one who raised Julius, and would remain a friend because of this bond. Mary Ann (the twins' mother) however, was told that Julius died at birth and was never told about Vincent. She blames Professor Traven for this (probably since he's the only one around to yell at). Vincent on the other hand was never told his mother died during childbirth and he grew up thinking his mother abandoned him. Until Julius showed up, he never knew he was part of an experiment and he had no knowledge of either doctors and probably no feelings regarding either of them.
Bishop73