When David is talking to Dr. Fields after saving her during a seizure, his hands alternate between being on the table and clasped together near his face from different angles.
During the final hulk-out scene Carolyn dies in the Hulk's arms and when David unhulks, he is still holding Carolyn in his arms, but on the ring finger of Banner's left hand is his wedding band, fully intact
When David returns from shopping, he finds the report papers scattered on the floor, however they are spread out in an organized way instead of falling randomly and out of order.
When Carolyn goes off to drink her sorrows away, she goes off with a random guy from the bar, David goes looking for her and gets a tip off where she is, he pushes his way into Brad's place and a fight ensues, when "Brad" throws David over the balcony you can clearly see it's a stunt double and not 'Bixby'.
During one of David's dream sequences, the Hulk breaks out of a bank vault type chamber in the desert. As the Hulk knocks the door down and exits the vault, two green hand prints from the green make-up can clearly be seen on the door.
At 57:07 one can really tell it is fake bald makeup used by the actor as it wrinkles at the joint with his forehead.
When David breaks into Carolyn's house he cuts his arm on the broken glass. In the insert shot his plaid shirt is a different color. It appears to be the shirt he wears in a later scene.
At 53:58 it is clearly seen that it is a stuntman thrown from the top floor and not Bill Bixby.
The entire episode is set in Hawaii. Near the end, a hurricane is approaching. Various segments of actual storm footage is intermixed with filmed scenes. One scene of boats being tossed about during an actual hurricane is used. Strangely, the boats all have Florida registration numbers on them, beginning with "FL". Indicating that the footage actually shows boats in a hurricane in Florida, not Hawaii; unless many Florida residents all decided to sail to Hawaii at the same time.
During the second hypnosis sequence when David has the Hulk trapped in a steel cage and is gassing the Hulk, you can see someone's head in a robe in the bottom left as David is putting on a gas mask.
The heavy spray from a water hose (causing the "rain") and the extension boom of the microphone are seen directly above Carolyn (Mariette Hartley) as she is spinning round and around during her seizure in the final moments of the episode.