38:41
Vampire blood is shown incorrectly stored in an un-spun serum separator tube, instead of an edta whole blood tube or no additive tube.
Stefan and Matt state that Damon is '100 miles out of town' and 'cannot get back within 1 hour'. However, as shown multiple times throughout the series, Damon is capable of running at many times faster than 100 mph, so fast that he is just a blur. He would have been able to return to Mystic Falls well within 1 hour.
Alaric is called Elena's guardian, but she has already turned 18.