Dr. Warner says that the suspect left three tooth marks on the chewing gum, his canine, premolar and molar. She compares it to the bite mark on the victim showing that the tooth marks on the gum are continuous. However, humans have three premolars between the canine and the 1st molar. Thus, it is impossible for the continuous tooth mark on the gum to be created from the specific combination of teeth Dr. Warner mentioned.
When Stabler and Beck jump the subway turnstile at 38:00 they are clearly not filming in NYC. Also, the signage doesn't indicate which 86th St station they are supposed to be in and the train never stops at the station.