You're right about the scene. And you're also right about the play—it's a tough one to make. But splitting 8s, rather than hitting or standing, against a dealer ten is always correct. In fact, splitting 8s is correct against all dealer up cards at all times, with two obscure exceptions against an ace—you should surrender 8,8 vs. A when the dealer hits soft 17 in 2 or more decks, and when double after split is allowed and the dealer hits soft 17 in 3 or more decks (as detailed in "Basic Strategy for Any Number of Decks" in Peter Griffin's The Theory of Blackjack). Hence, the comment made in the coffee shop was wrong ... that is, if they were really talking about basic strategy.
Remember, 21 is about counting cards, and that play could easily be correct when the count is considered. We'd bet that the error in the dialogue was due, not to a mistake in the technical advice, but rather to a mistake in editing. What if earlier in the scene there was a discussion about making deviations from basic strategy at high counts. In the high-low count system, which is the system used by the MIT players, you should stand on 8,8 against a ten with a true count of +6 or higher. If the editors didn't understand the significance of deleting the first part of the scene, they would be the cause of the mistake being made.
Regarding the movie's "technical soundness," it's true that most of the mathematical explanations were right on. However, tremendous license was taken in other areas, especially concerning the level of retaliation by the counter catcher (Laurence Fishburne). Other areas where the movie was off were in the depiction of Las Vegas (several casinos that were focal in the movie did not exist at the time that the subject MIT count team was in action) and the depiction of the team itself (it was almost exclusively made up of Asians).
And here's a real inside look. Kevin Spacey’s character, Mickey Rosa, was patterned after the real-life MIT team leader and Blackjack Hall of Fame member, John Chang. John was so dismayed by the inaccuracies that he put up a website to refute some of the movie's assertions. The website hasn't been updated since 2008, but you can still check out John's comments, as well as get a look at some high-level blackjack theory, at mickeyrosa.com.
