From SWAT's beginning, the most widely accepted interpretation of who's in charge is that once a situation has been turned over to SWAT, the SWAT Commander is in charge of all tactics. This is simple, effective, and works in theory, but not always in the real world where the human element is a factor.
Red Light, Green Light
Early in SWAT, the buzzword was "green light," meaning authorization for use of force by SWAT. However, many police brass interpreted it as "red light," meaning SWAT not allowed to use force or do anything "aggressive." Sound familiar? It took SWAT years to eliminate the "green light" system. End of problem, right? Unfortunately, not for a growing number of agencies and SWAT teams.
For a period of years, SWAT retained overall charge of on-scene tactics once the situation had been turned over to the SWAT team. The advantage is obvious. SWAT is trained, equipped, and specializes in tactical solutions with an impressive track record of success.
However, for many agencies the pendulum seems to have swung back to the early days of "green light." The new interpretation goes like this: SWAT isn't allowed to do anything "aggressive" without direct authorization from the chief, sheriff, or field commander. Additionally, any and all SWAT tactics must be pre-approved before being implemented. To me, this sounds like a big step backward.