Mei's dad's glasses fog up while cooking. He takes them off, but wipes off only one lens. When he puts the glasses back on, both lenses are clear.
(at around 7 mins) Meilin has 4 incense sticks in her hand, lights them, and hands 3 to MeiMei. In the next shot, Meillin has 3 sticks, and MeiMei has 2.
When the 4*Town members are stuck in the angel wings, Robaire is in the center. Later, when the 4*Town boys are waiting below, Aaron Z is in the center while Aaron removes his wings.
The streetcar driver holds a steering wheel. Streetcars run on rails, and can't turn freely like a bus.
After Meilin's mom sends her sisters off to a hotel, she looks up at a crescent moon, which faces the wrong direction. Crescent moons always point toward the sun, and inner arc begins and ends at the lunar poles, not toward the moon's equator.
At 1:03, when the "Red Moon" lunar eclipse is beginning, the view presented of the moon is entirely incorrect. A lunar eclipse begins with a small arc being shaded on the surface of the Moon from the circular shadow of the Earth - almost as if a larger and larger "bite" is being taken from the Moon. A darker circle being superimposed over the lighter one.
The camcorder that the girls are using say that it's May, but the cherry trees are blossoming, which they only do in March/April.
The movie shows a lot of 2001 Canadian Journey banknotes. The $10 bill was introduced in 2001, but the $5 bill was introduced on March 27, 2002, so it's not likely that so many students would have them.
Two characters have continuous glucose monitor patches on their upper arms. CGMs first appeared in 1999.
Lester B. Pearson Middle School has a sign for Canadian Indigenous People's History Month. It's actually called National Indigenous History Month, and it was first observed in 2009.
The CN Tower's elevator shafts emit purple light during the 4*Town concert. That wasn't possible until 2007, when an LED lighting system was installed.
The sprinkle Timbits ("donut holes") at the top of the Tim Horton's box are "birthday cake" flavor. The film is set in 2002, Tim Horton's launched that flavor in 2014 as part of its 50th anniversary.
A person in a wheelchair uses a lift on a TTC streetcar. In 2002, TTC streetcars did not have chair lifts.
One of Stacey's friends has an LG L1400, which was released in 2004.
The name "Sun" in "Sun Yee" is mispronounced throughout the film, with the characters saying it as "sun" (like the solar body) instead of the correct Mandarin pronunciation, which uses a sound closer to "soon" or "swun." This pronunciation error is inconsistent for characters of Chinese heritage.
When the aunties try to stop Meimei from leaving the temple grounds, one of them clearly says "Yamete," which means "stop" in Japanese. This is inconsistent with the fact that all the aunties are Cantonese-speaking Chinese Canadians, making the use of Japanese out of place.