Special Branch

The finer details of the conspiracy in Sweeney! are somewhat murky, but i think this is one of the films great strengths- why should everything have to be spelled out for the audience? Such ambiguity was far more common in 70's films- look at the ending of the original "French Connection"! Nowadays everything has to be spelled out to audiences who can't be botherd to think for themselves, which is a shame- i think Sweeney! is one of the finest crime thrillers of the 70's, certainly one of the most underrated!
Now ok, that doesnt excuse sloppy plotting- but i think i can answer most of the queries raised on this thread....
1) Johnson and Johnson were't special branch, but special branch knew what they were doing and did nothing- because, as the PPS says at the end to Regan "people like McQueen are above arrest inspector." Maybe in reality as hitmen they'd've been a little more circumspect, granted- but the central point, that international oil companies and those who work for them are too powerful to be constrained by laws, seems fairly believable to me. So at the climax, realising he couldnt arrest & charge McQueen for murder, Reagan instead engineered a situation where he'd be killed by his employers "This is going to prove that even YOU are expendable!"
2) It's hinted at throughout the film that special branch, while not directly involved in the conspiracy, know what's going on and are merely determined to cover it up as far as possible. After the massacare at the scrapyard for instance, a special branch officer turns up and asks what Regan and Carter are doing there. Why, when at that point it's thought to be merely a run of the mill gang war? Also, after the uniformed constable is shot by Johnson, listen to the news report on the radio while Regan and Bianca are hiding out in Carter's flat...the description of Johnson's car is wildly innacurate. Again, why? I can only conclude that special branch are again involved.
3) "It's a bit of a stretch for them (special branch) to willingly go after another copper". Special branch had no choice but to look the other way while Johnson and Johnson were trying to kill Regan.....their loyalty is first and foremost to the country, and diffusing threats to national security- as opposed to the regular copper who's priority is to catch criminals. If the conspiracy orchestrated by McQueen on behalf of international oil had got out, the goverment would've collapsed- they were looking at the bigger picture, and to them Regan shouldnt have been interfering in the first place.
Anyway, that is my opinion- i'd be fascinated to hear what others think!