Revealing mistake: When Eli and Klitz are being chased by Mule, Eli and Klitz go over the railing and land on the table. After that when Mule lands on the table you can see the table break a split second before he lands on it.
Revealing mistake: Just before the security guard smashes his car into the oncoming car, you can see he has been replaced by an stunt dummy. (00:09:25)
Revealing mistake: When Matt is chasing Dannielle's car naked, it is clear that a body double is being used as he is taller and has lighter color hair than Matt.
Answer: While it doesn't have anything to do with the overall plot, the crash shows just how much Matthew is afraid to do the wrong thing and perhaps how he overthinks things. As we know all he would be doing is missing a bit of school by getting in his car and driving from the school. The fact that Matthew is able to imagine an horrific crash of a security guard because of just skipping school shows how worried he is about doing the wrong thing.
Lummie ★