Another Mother - September 30, 1981 - S2-E13
Factual error: When the boys are talking to Jackie to get her to cooperate with their plan, the song Shake It Up by The Cars is playing, except the show is set at September 30, 1981, and the song was released in November 1981. And it wasn't a pre-release demo version on the radio since the song was still being mixed at Syncro Sound Studios in early October. (00:23:00)
Another Mother - September 30, 1981 - S2-E13
Plot hole: Sam wallops both kidnappers and rescues the son. They then leave the two child molesters unconscious beside their van. No one calls the police or has them arrested, so they're free to kidnap another kid. Sam doesn't leap until after an epilogue in which the loose ends are supposed to be resolved - but this question is left unanswered. It's not excused by a "just because we didn't see it happen doesn't mean it didn't" defense. The viewers shouldn't be left with a dangling plot hole, and one line could have cured this one.
Another Mother - September 30, 1981 - S2-E13
Revealing mistake: When Sam and Al are in the station wagon pursuing the van, both Sam and Al's reflections are visible on the wagon's front hood. Al, as a hologram, shouldn't have one and Sam's reflection should be as Kevin's mom.
Another Mother - September 30, 1981 - S2-E13
Visible crew/equipment: After going to get pizza, Sam and the kids return home. As they pull in the driveway a long boom mike is visible in the back car window.
Another Mother - September 30, 1981 - S2-E13
Continuity mistake: When Sam uses martial arts against the men from the van, one of them pulls a knife as he kneels on his right knee in the close-up, but next shot he is kneeling on his left knee.
Another Mother - September 30, 1981 - S2-E13
Continuity mistake: When one of the sicko men from the van pulls a knife on Sam, the white blouse is either tucked into the skirt or hangs over it, depending on the shot.
Chosen answer: Per the Quantum leap page at http://www.scifi.com/quantum/episodes/season5.html. 8 August 1953: An enigmatic leap lands Sam in a Pennsylvania tavern, as his own grown self on the day of his birth. As Al and Gushie work frantically to locate him, Sam befriends a wise bartender (popular character actor McGill, who'd appeared in a different role in the very first "leap") and a group of coal miners. As a host of familiar-looking faces pass through the bar - with different identities than Sam remembers - Sam ponders his life of leaping with Al the bartender, who tells Sam he controls his own destiny. Pressed for more, Al the bartender simply shrugs and says, "Sometimes, 'that's the way it is' is the best explanation." Sam realizes he must right at least one more wrong before he can go home, and leaps back to tell Al Calvavicci's wife Beth (from "M.I.A.") to wait for Al, who will survive Vietnam and come home to her. The closing title cards state that Beth and Al have four daughters and will shortly celebrate their 39th wedding anniversary ... and that Sam Beckett never returned home.
Boobra