While Rollins and Carisi are interviewing Roger at his job, the clock in the background changes from 12:38 to 12:33 to 12:39, indicating that the footage used in the scene was taken from multiple takes filmed over at least six minutes.
When the detectives are interviewing Tyler he can be seen putting his coffee cup down on the table (shot from behind). However, when the shot is changed to in front he again puts his coffee cup on the table.
Rollins tells the dealer that he is under arrest for "possession of a class-A drug with intent to distribute". The term "class-A" is actually not used in the United States, that is a term used in the United Kingdom and other European countries. The U.S. analog to the U.K.'s class-A is Schedule I, Schedule I controlled substances have no recognized legitimate medial use and cannot be prescribed. However in the United States cocaine is not a Schedule I controlled substance, it is Schedule II meaning it can be prescribed by a properly licensed physician but it is heavily regulated, though cocaine is rarely prescribed these days. It used to be popular as a topical anesthetic for eye and nose surgery, but for the most part has been replaced by safer drugs that function better (like Novocaine and lidocaine). It is still used occasionally by ENT doctors doing nasal surgery to help reduce bleeding as cocaine is a potent vasoconstrictor.