Factual error: Hy-Vee is a $10 billion retailer with its own Hy-Vee private label. The Hy-Vee store Kurt is working at and shopping at in the movie erroneously is not carrying Hy -Vee Private Label, but rather, carries Best Choice and Always Save which are AWG's private labels. Associated Wholesale Grocers is a $22 billion wholesaler that supplies independent Grocers all over the country, but not privately held chains like Hy-Vee or Kroger which have their own private labels.
Factual error: Kurt Warner worked in the Hy-Vee grocery store in 1994. The Wheaties box he took off the shelf featured Dan Marino #13, which was available in 1995. A 1994 Wheaties box featuring the NFL 75th Anniversary Collectors Edition had a different design and color. Unless Kurt also worked in the store into 1995, the Wheaties box he held in the movie was not yet available. (00:39:50)
Character mistake: Zack's birthday cake appears to have his name misspelled as "Zach." (00:29:24)
Other mistake: After seeing Joe Montana play in Super Bowl XIX, young Kurt said, "I knew I wanted to be that guy." When he goes outside to pass the football, young Kurt has "Warner 13" on the back of his jersey - not Montana's #16 but the #13 that he could not know in advance that he would eventually wear during most of his adult career. (Jersey numbers are not necessarily that available for a player to have his pick). (00:02:02 - 00:02:33)
Suggested correction: This is trivia at best, certainly not a mistake. While it's true he wore #12 in high school, there's no reason he couldn't have liked #13 as a child. And, many key position players do get to pick their number, from the available range, which Kurt certainly did.