Corrected entry: The opening scene of the movie depicts two small aircraft (one is a Beechcraft Bonanza) colliding in midair and falling in the playground at Pacoima Junior High School. This accident did occur on January 31, 1957, but the aircraft involved were an Air Force F-89 jet fighter and a four-engined DC-7 airliner, and only the DC-7 hit the schoolyard. A young Latino boy is among those killed on the ground, and Ritchie Valens refers to him as "my best friend". In reality, the three boys killed at the school were Anglo and were 12 and 13 years old - two or three years younger than Ritchie at the time.
Corrected entry: The film depicts the coin toss between Valens and one of Holly's band members, Tommy Allsup, as having taken place at the airport shortly before takeoff, with Holly having tossed the coin. In real life, the coin toss took place at the Surf Ballroom when Tommy Allsup, after being asked numerous times by Valens to "let me fly", finally pulled a fifty cent coin out of his pocket and said "Call it." Valens called heads and won.
Correction: There are at least 3 different versions to this story, all from people who were there. We will never know what really happened with the coin toss because none of the survivors agree on it.
Corrected entry: When Ritchie is playing in the restaurant, his mother takes a big drink from a glass. But a moment later, the glass is nowhere to be seen.
Correction: The glass is actually a hidden a little behind her chair and remains there for the 3 or 4 shots of her before she gets up to dance.
Corrected entry: The bulletin of the plane crash announces J.P. Richardson (The Big Bopper) as being 29 at the time of his death. He was actually 28, and he would have turned 29 in October of that year, had he lived.
Correction: That's a common occurrence in real life. When a person has a birthday late in the year, like me, people usually take the year it is, minus the year of birth, and say that's the person's age, not taking into account being born in the autumn or winter. For example, 2009 - 1969 = 40, so most people would just assume the person born in 1969 is 40, not 39 about to turn 40.
It's not that common to do (and even less common at the start of the year in Jan or Feb). When people are discussing someone's age, especially famous people and their deaths, they say what their age actually is and not what age they would have been. For example, Chadwick Boseman is said to have died when he was 43, despite being 3 months from turning 44.
Correction: Just because the kids that died were younger than Ritchie doesn't mean one of them couldn't have been his best friend.