The Leap Back - June 15, 1945 - S4-E1
Corrected entry: It is accepted canon that Al sees Sam as the person he has leapt into, and Sam of course sees Al as Al. Therefore, at the beginning of this episode, Al would have been shocked to see Sam standing next to him, while Sam would not have recognized Al, but rather would be looking at Tom the soldier that Al has leapt into. However, they are unaware of the role reversal until Al walks into the cannon on the lawn.
Genesis (2) - September 13, 1956 - S1-E2
Corrected entry: At the end of this episode, Sam has leapt into the body of a baseball player and realizes he's there to win the game. Sam swings the bat but misses the ball three times. He should have been struck out, but instead run the bases, winning the game.
Correction: This episode employed the uncaught third strike rule (rule 6.05 and 6.09) if the back catcher fails to properly catch the third strike of the third strikeout (or if there's no runner on first), the batter becomes a runner and can pursue a home run, which is what Sam did.
Dr. Ruth - April 25, 1985 - S5-E14
Corrected entry: Towards the beginning of the series, it was established that Sam often spent weeks "bouncing" around time before landing in somebody's life to change the past - this transition is seen as instantaneous from Dr. Beckett and the audience's perspective. However, when Dr. Ruth leaps back into her own time at the end, she's instantly replaced by the next person.
Correction: It was established that the length of time was rather variable - it was often of the order of weeks, but often does not mean always. As such, there's no particular reason why the next person couldn't show up immediately.
Mirror Image - August 8, 1953 - S5-E22
Corrected entry: In Good Morning, Peoria (series 2, episode 6), when Sam is creating a makeshift aerial on the roof, Al starts glowing blue, as Sam does when he leaps. He says "Look Sam, I'm leaping." However, in this episode, Sam sees someone else leap. When Al appears, Sam excitedly tells him about it and asks Al if he goes all blue and charged with electricity when he leaps. Al responds by saying that he wouldn't know, as when Sam leaps he simply finds himself back in the imaging chamber. If Al has never seen this why would he have assumed he was leaping in an earlier show?
Correction: Sam's leaps would also affect the people at Project: Quantum Leap (as seen in "A Leap for Lisa"). As well as "Good morning, Peoria" where Al thinks he's leaping, in "Future Boy" Al sees Moe Stein begin to leap before his machine breaks (Al visibly reacts). One of Sam's leaps after these episodes has changed something at the Project so Al gets sent back before Sam leaps.
How the Tess Was Won - August 5, 1956 - S1-E5
Corrected entry: The ranch is 50,000 acres, which is around 78 square miles. This is about 3.5 times the size of Manhattan Island. Yet they only appear to have four or five ranch hands to cover all that land, which would be impossible.
Correction: Just because we only see a handful of ranch hands doesn't mean that's all they have. And in one scene, I see 6 ranch hands, so there's more than just 4 or 5.
Trilogy (3) - July 28, 1978 - S5-E10
Corrected entry: Sam, and not the man he leaps into, somehow fathers a daughter with Abigail. Al and Ziggy's answer to "How?" is "We just don't know." Since Sam has always leaped into the physical body of his subjects with no trace of his own physical presence (yes, we see Sam, but no one else does), fathering a child with his own DNA should be impossible. And the characters acknowledging the "mystery" does not excuse the breach of previously established series canon: it merely makes this, at the very least, a deliberate mistake.
Correction: It is explained several times within the series, particularly in 8 1/2 Months, that Sam himself is physically making the leaps but that he occupies the aura of the leapee - this is why others do not see him as Sam. This is also shown to be the case when he leaps into a blind man but can still see or a man with both legs amputated and yet Sam can walk. This being the case, it doesn't seem impossible for him to have fathered a child during a leap and does not go against canon in suggesting he did.
Nowhere to Run - August 10, 1968 - S5-E4
Corrected entry: For four seasons, we were told that Al always saw Sam as the person he'd leaped into. (Case in point: Al once suffered an attack of guilt-ridden lust when Sam leaped into a very attractive woman.) Here, that series canon is violated when Al tells Sam, "Nobody sees you except me. Everyone else sees the real Miller." (00:21:10)
Correction: There was at least one prior example of Al seeing Sam as Sam, in the episode "Miss Deep South". So the changed premise happened much earlier than written here.
Corrected entry: For those not familiar with the show, a scientist named Sam leaps into peoples' bodies and changes their futures. Us viewers see the person as Sam, but characters in the show still see the person Sam has leapt into. So when Sam leaps into a child or a short person, the other characters should technically be looking at Sam's chest when they are trying to look him in the eyes because that's where their eyes would be. Instead, they always look right into Sam's eyes - too high if you are really talking to a child or short person.
Correction: Remember God, Time or Whatever wants Sam to complete his missions with a minimum of fuss & hassle so things will change to how it wants so if Sam is trying to gauge someones reactions he would need to see their expressions. Also if something can make Sam journey through time whats to say it can't force someones perception so they actually do see things how they are meant to be whilst looking into Sams eyes, as we don't know the extent of the things powers we can't make a guess as to its limits.
How the Tess Was Won - August 5, 1956 - S1-E5
Corrected entry: Sam meets a young Buddy Holly and hears him sing "Peggy Sue" for the first time. Unfortunately, that song was originally called "Cindy Lou."
Correction: While this is true, we don't know if he'd already changed the name before the first time he sang it. The poster doesn't seem to have paid much attention as he was singing "Piggy Sue" and Sam tells him to change it to "Peggy Sue". He got the name "Peggy Sue" from a girl who was dating one of the band members so the "Piggy Sue" part could be considered an error because he certainly never sang it that way.
Correction: While it was canon in early episodes (notably "What Price Gloria") that the Observer saw Sam as the Leapee, by the time of "Miss Deep South" (which originally aired well before "The Leap Back"), it is clear that a change has been made so that Al sees Sam as Sam. In that episode Al says that Sam looks "like Scarlett O'Hara on steroids." So for Sam and Al to initially not realize that something strange is going on at the beginning of "The Leap Back" is not a plot hole.