While we are told that, it is also true that none of the other arrestees that were in the paddy wagon that day complained of broken necks.
Also true is that Freddy tried to use the injury technique multiple times previously to try to get out of having to stay in a jail cell.
But if it was an open secret that the cops played this "nickel ride" game with suspects - even if they only did it with the real bad actors - that's a problem. Baltimore PD management should have been on it a long time ago, although we all know how things work in real life... management individuals undoubtedly took people on "nickel rides" themselves when they were in the ranks.
In the 21st century, when there are video cameras all over the place and lots of outside scrutiny, the "unwritten rules" that used to be used to keep the bad guys in line now can't be kept in the shadows any more.
It used to be a well known fact among the bad guys that if you crossed certain lines with the cops, you were going to get put in a world of hurt. The cops knew it, the criminals knew it, the judges and prosecutors knew it, and the mayor's office knew it too.
That kind of system ("extra judicial punishment") started to go out in the '60s, and it's still being phased out today (although I suspect other sorts of EJP modalities have emerged to take the place of the old ones; this comes under the general concept of "you can't fight city hall").