When Jenn pours Janis's second drink, she pours the booze to the very rim of the glass in the closeup, but in the subsequent wide shot, the booze is almost an inch from the rim.
When Ben has leaped into the body of a US Army colonel, two servicemen salute him. He returns the salute, but the two servicemen drop the salute and walk away before he drops his. Servicemen are not allowed to end a salute before the superior officer they are saluting does.
Ben, as Dr. Thompkinson, uses a defibrillator to restart a patient's heart. Defibrillators do not start a stopped heart. They are used to stop a heart that is beating arrhythmically with the intention of the heart restarting (either naturally or via manual intervention) with a normal rhythm.
Hospitals do not put signs with the patient's names on them outside of exam rooms, nor would they label a clipboard in giant letters.
While showing the cityscape of Seattle, Lumen Field, T-Mobile Park, and the Seattle Great Wheel can be seen. These three buildings were built in 2002, 1999, and 2012, respectively. This episode takes place in 1994.
When Ben Song is speaking with Addison for the first time, the song "In the Meantime" by Spacehog is playing in the background. Ben leapt into a doctor in 1994; however, the song was not released until 1995 on the album "Resident Alien" and, therefore, could not have been playing during this leap.
When Lewis Tan first appears, discussing the train crash and asking for his wife, his voice does not match his mouth movements.
Ben was able to open Alexandra Thompkinson's work locker, which has a combination lock. As Ben does not gain the leapee's memories while inhabiting their lives, he would not have known the combination.
Addison refers to Seattle 1994 as the height of the Grunge movement. Grunge began in Seattle in the 1980s and peaked in the early 1990s. By 1994 its popularity was in decline.