Texas Immunity?

Walker, the Texas Ranger, busts a drug-packaging operation with a small army of other Rangers. Cue a big punch-up with white powder flying all over the place.
    How come the forces of law ‘n’ order didn’t get wiped out on the drug, letting the bad-guy packers, who were wearing filter masks, leg it?
    Because we were in the last five minutes and the show had to be wrapped up. Real world logic defied.