When Dan kills Dr. Rigas, his face and exposed skin do not glow like all the other victims Dan electrocutes. This may be because he wasn't in direct contact with Dan. Rigas dies when Dan's current is conducted through a doorknob.
While the film shows a bus skidding into a high tension tower, the newspaper article about Dan McCormick leaving the hospital states it was an accident with an interurban car and an oil truck.
After Dr. Rigas has infused Dan McCormick with electricity, sparks begin to erupt from Dan's fingers. Leaving the laboratory, he reaches toward a glass goldfish bowl, which seems to attract the electricity in his body. But glass is an insulator; only a grounded, electrically conductive substance would attract the sparks.