Blooper

The dumpster changes colors from blue (before Robbie is in it) to black to red while Robbie is in it.

The limousine loses hubcaps while driving, but they soon reappear on the wheels.

The number of cake pieces on the plate in the bakery changes. When Robbie turns to feed the lady, there are two pieces left, but in the next shot, the plate is empty.

During the song "Holiday," the band-aid on Robbie's left ring finger disappears.

When Robbie is in the dumpster there is a chain across his body in one shot and in another shot it's gone, but they go back to him a third time and it's across him again.

Julia's wedding is set for "Sunday," August 5, 1985. This date fell on a Monday.

The DeLorean used in the film is missing the DMC logo on the front grille.

Although purportedly set in 1985, there are numerous 1980s references (including, but not limited to, the Rubik's Cube, assorted songs, TV shows and fashions) which could only exist in earlier or later years. While technically anachronistic, it seems reasonable to allow them since the intention is clearly to produce a portrait of overall nostalgia for the decade, rather than a strictly accurate historical recreation of a specific year.

The meatballs that get squished in Robbie's hands disappear. That's because they are squished; they are no longer balls. The remains can be seen either falling to the floor or sticking to Robbie's hands.

In all of the exterior shots of the airplane flying above the camera, the landing gear is still out.

Set in summer, yet the trees have no leaves and people are wearing jackets throughout.

After Robbie buys his ticket to Vegas, the shot of the the plane's exterior shows it is a twin engine single deck plane. The interior shots of the first class section show a spiral staircase leading to an upper deck. At the time, the Boeing 747 was the only plane with an upper deck. The 747 has four wing mounted engines, not two.

When Sammy is laying in bed next to Robbie, right before the camera cuts away after Sammy says "I'm just trying to get someone to play with your ding dong," you can see Adam Sandler smile out of character.

Frank and Rosie are supposed to be celebrating their 50th anniversary. However, the picture on the wall of their wedding is dated 1948, which is attuned to the film's release date in 1998. The film is set sometime in the 1980s.

There is a LEGO set on the floor that wasn't made until 1997, too late for the "sometime in the 1980s" setting.

When Julia and her friends are at Carvel choosing what kind of cake she wants, the pink Carvel banner with confetti is from the 1990s.

The guitar that the guitarist in the Robby Heart band is playing is a 1990 Gibson Les Paul Custom Plus.

Andy says he's watching Dallas and he thinks J.R might be dead. J.R was shot in an episode that aired in 1980, not 1985.

When Julia is picking out someone to dance with at the bar mitzvah, the boy who pops his jacket and says "Pick me Julia" voice doesn't fit with his mouth.

At the Bar Mitzvah, when George is playing the clarinet, his left hand only has his index and ring finger covering the holes. There is no note on the clarinet with that fingering.

At the very beginning of the song "Love Stinks," a loud snare drum hit can be heard but the drummer's hands do not appear to be moving, at least not in the way they should for a loud snare drum hit. In addition, for the remainder of the song, a hi-hat sound can be heard but the drummer's right hand is hitting the snare drum. Drummers typically use their right hand on the hi-hat.

With the footage of the exterior of the aircraft, the logo for Canadian Airlines can be seen, yet they are flying from New Jersey to Nevada.

On the way to the airport, the scenery is that of the desert.

Robbie tells Linda "Get out of my Van Halen t-shirt before you jinx the band and they break up" That would have been on August 4, 1985 the day before the wedding was supposed to happen. However David Lee Roth had already left Van Halen on April 1, 1985.

When flying to Las Vegas, Julia remarks that she would like to see the lights of Vegas from the plane. However, the plane was a daylight morning flight flying westerly from New Jersey. As the flight would take 4 hours, even if they would leave NJ at 5am and they would arrive at 7am in Vegas time. So there's no way they would arrive at night to see the lights.

During the Bar Mitzvah when George is playing the clarinet, both of his lips are sticking out like he's playing a kazoo, including his lower lip, which should be positioned between the reed and his teeth.

The Rolling Stone Julia is reading is dated January 31 and is in perfect condition. As the scene is set in August, it should have some wear (she does not have it when she boards the plane).